Wbridge5 is a prominent bridge program. Wbridge5 has been world champion of the bridge programs in 2005, 2007, 2008, 2015, and 2016. Besides excellent playing, this program also employs a dedicated bidding system. This book is a technical report of that system as Wbridge5 5.12 bids it. There is also a collation in Full Disclosure format.

The topic of this book is bidding. Card play is left out except for the opening lead and defensive signals, which are agreements between partners like the bidding.

Wbridge5 has a 2/1 bidding system with French flavors, as it originates from France. Some French conventions greatly improve bidding structure from the American, so Wbridge5 incorporates them. Others not so profitable are not included in Wbridge5.

Each chapter describes what Wbridge5 bids, verified by probing the program itself over the Table Manager protocol. The probe harness and its data are in the source repository. The chapters also compare the probes with the 2011 writeup, the author’s 2009–2011 Chinese writeup of the system: Wbridge5 humanized, with improvements for human players by the principle of useful space. Where the two differ, the probe wins. Rules from it and other older writeups that 5.12 does not play are archived outside this book as optional agreements.

Wbridge5 sits South in every probe. The harness plays the other three seats from a fixed auction and deals South random hands under constraints on shape and HCP. The dealer is set so that South calls right after that auction, whose first call is thus in 1st seat. South opens in 1st seat unless the auction starts with passes, and its direct overcalls are in 2nd seat. Nobody is vulnerable unless a chapter says otherwise, and the opponents play Wbridge5’s own system unless a chapter names SEF or SAYC. An auction usually gets 300 boards, up to 1000 for rare calls. Wbridge5 makes South’s earlier calls in the auction itself, and a board where it strays from the script is dropped. A range in this book is what Wbridge5 bid on the boards kept, so a rare hand at its edge may bid otherwise.

Notation

This book follows Strawberry Polish Club for bidding notation and punctuation in tables and prose. Hand evaluation is Wbridge5’s own, described in its chapter.

References

• Yves Costel. Wbridge5
• Chen-Pang He. Wbr5.bss
• Chen-Pang He. Strawberry Polish Club
• Thomas Andrews. Thomas’s Bridge Fantasia

License

The source code is hosted on GitHub. Feel free to share or improve this book. The content is released under CC BY-SA 4.0. The source code is released under GPLv3+.

Hand evaluation

Wbridge5 mainly uses point-count system for bidding. One counts mainly honors for notrump contracts and defensive values, with distribution points combined for suit contracts. The losing trick count helps evaluate distributed hands for suit contracts.

High card points

Wbridge5 employs the well-known 4-3-2-1 count.

• Ace: 4 HCP
• King: 3 HCP
• Queen: 2 HCP
• Jack: 1 HCP

Distribution points

• Void: 3 points
• Singleton: 2 points
• Doubleton: 1 point

Probing Wbridge5 5.12 shows that the doubleton counts at the top of the 1NT opening too, but not at its bottom. Of balanced 17 HCP hands, 70 of 79 with 4-3-3-3 opened 1NT against 88 of 130 with 4-4-3-2, and only 12 of 36 hands with 4-4-3-2 or 5-3-3-2 whose doubleton held no honor. At 18 HCP, 44 of 79 hands with 4-3-3-3 opened 1NT, and 25 of 126 with 4-4-3-2. At 14 HCP, 3 of 143 hands with 4-4-3-2 opened 1NT, and none of 66 with 4-3-3-3.

Refined honor points

Wbridge5’s help says that the program adjusts the 4-3-2-1 count for unguarded honors and sequences. Probing Wbridge5 5.12 shows these adjustments where a point decides the opening: at the edges of the 1NT range and in hands that open by the rule of 20. Each is worth a point or less, except a singleton king or queen. For comparison, Thomas’s Bridge Fantasia provides precise published evaluators. They are not Wbridge5’s.

Aces, 10s, and 9s

Aces count more than 4 HCP, while 10s and 9s count a little. At the top of the 1NT range, they move balanced hands (4-3-3-3, 4-4-3-2, or 5-3-3-2) to 1 of a suit. Logistic fits to these 523 hands value an ace at 1/3 to 1/2 HCP above its 4, a 10 at about 1/4, a 9 at about 1/5, and the doubleton at 3/4 to 9/10, depending on whether honors in the doubleton enter the fit.

At the bottom, 10s rarely lift a hand to 1NT. All 300 hands with 15 HCP, 2–4 cards in each major, and 2–5 in each minor opened 1NT, the 12 with no ace too. Of 300 such hands with 14 HCP, 5 opened 1NT, all with a 4-4-3-2 or 5-3-3-2, 2 or 3 aces, and one to three 10s. Hand ladders with 14 HCP add 10s one at a time:

• ♠A84 ♥K73 ♦QJ62 ♣A85: Open 1♦, still with four 10s (♠A104 ♥K103 ♦QJ102 ♣A105) or with every spot a 10 or 9 (♠A109 ♥K109 ♦QJ109 ♣A109). So do another 4-3-3-3 with no ace and a 4-4-3-2 with one.
• ♠A109 ♥A109 ♦A1098 ♣Q109: Open 1NT with 3 aces, four 10s, and 9s. Four 10s alone (♠A104 ♥A103 ♦A1062 ♣Q105) or 9s alone (♠A98 ♥A97 ♦A986 ♣Q98) open 1♦.
• ♠A104 ♥K103 ♦102 ♣AQJ105: Open 1NT with four 10s and a 5-card minor. Three 10s open 1♣, unless 9s back them (♠A109 ♥K109 ♦109 ♣AQJ85 opens 1NT).

Ladders with 17 HCP cross the ceiling only with aces and 10s together:

• ♠A104 ♥A103 ♦KJ102 ♣AJ10: Open 1♦ with 3 aces and four 10s. With three 10s (♠A104 ♥A103 ♦KJ102 ♣AJ5), open 1NT.
• ♠AQ10 ♥KJ10 ♦QJ102 ♣A105: Open 1NT with 2 aces and four 10s. So does ♠KQ10 ♥KJ10 ♦KJ102 ♣KJ10 with no ace.

Ladders with 18 HCP turn on the aces:

• ♠KQ4 ♥KQ3 ♦KJ62 ♣KJ5: Open 1NT with no ace. ♠A84 ♥A73 ♦AQ62 ♣A85 with 4 aces opens 1♦.

Unguarded honors

A singleton king or queen loses at least a point. Of 5-4-3-1 hands with 11 HCP and a 5-card spade suit, all 107 with a small singleton opened 1♠, but none of 19 with a singleton king or queen, 4 of 13 with a singleton jack, and 5 of 6 with a singleton ace. With 10 HCP, 10 of 102 hands with a small singleton opened 1♠, 9 of them with all 10 HCP in the two long suits.

• ♠AQ852 ♥Q763 ♦K84 ♣9: Open 1♠.
• ♠AQ852 ♥Q763 ♦984 ♣K: Pass. So do the twins with a singleton queen or jack, and the singleton-king twins with five hearts or five clubs.
• ♠KQ852 ♥Q763 ♦984 ♣A: Open 1♠, as with the ace in the 3-card suit.

Two honors in a doubleton, AK excepted, cancel about the doubleton point, and so does a doubleton queen. At 18 HCP, 4-4-3-2 and 5-3-3-2 hands opened 1NT only with such a doubleton: 12 of 13 with AQ, 7 of 8 with KQ, 4 of 9 with AJ, 3 of 8 with KJ, and 6 of 20 with Qx. None of 128 with a small doubleton, Ax, Kx, Jx, or AK opened 1NT. At 15 HCP, no doubleton moved a hand down to 1 of a suit.

• ♠AQ84 ♥KQJ3 ♦AQ6 ♣84: Open 1♦ with 18 HCP.
• ♠AQ84 ♥J873 ♦AQ6 ♣KQ: Open 1NT, and so with ♣QJ (♠AQ84 ♥K873 ♦AQ6 ♣QJ).
• ♠KQ84 ♥873 ♦AQ62 ♣AK: Open 1♦.

Binky

Binky is a theoretical evaluator impossible for a human player to use. To obtain Binky points, one looks up an exhaustive table for every pattern and holding. This evaluator is regarded as a reference here.

Fifths and Bum-rap

Wbridge5’s help names neither, so these two evaluators, for notrump and suit contracts, are archived with the adjuncts.

Additional distribution points

Thomas has not justified these point-adding systems popular in France, but the Wbridge5 program uses them.

Length

Add 1 point for the 6th card and thereafter in every suit. The French help says so (“plus de cinq cartes”), while the English one counts only cards “in excess of 6”. The probes below cannot tell the two apart: a 6th card in the trump suit also makes a 9th trump, and it replaces a 4-card side suit.

Fit

Wbridge5 does not document fit points. The French help says that once a fit is agreed, the program counts support points. Probing Wbridge5 5.12 shows a point for the 9th trump and nothing for the 10th. A 4-3-3-3 hand bids as if one point short: either it does not count the 9th trump, or its flat shape costs a point.

Responder to 1♠ without a singleton or void bids as follows. The rows with a doubleton are hand ladders adding one honor at a time in the side suits, alike with the honors in hearts and diamonds or in diamonds and clubs. The 4-3-3-3 row comes from 300 random hands with 3–5 spades and 5–13 HCP, which bear out the other rows.

With four spades and a doubleton, the Bergen ranges in the raise structure are HCP plus 1 for the doubleton plus 1 for the 9th trump: 3♣ at 9–10 points, 3♦ at 11–12. With 4-3-3-3, 2♠ and 3♣ come 2 HCP higher, a point for the missing doubleton and one more, and 2NT replaces 3♦. With 3-card support, 4-3-3-3 hands raised to 2♠ with 7–10 HCP, a point above the hands with a doubleton, and bid 2NT from 12, two points above. The 5th spade only makes the weak raises preemptive: 3♠ at 5–6 HCP, and on the random hands 4♠ on 9 of 20 boards with 6–8 HCP, mostly 5-4-2-2.

• ♠7643 ♥A987 ♦K98 ♣65: Bid 3♣ with 7 HCP.
• ♠76432 ♥A98 ♦K98 ♣65: Bid 3♣, the same as with four spades.
• ♠764 ♥A987 ♦K987 ♣65: Bid 2♠.

The opener counts likewise. After 1♠ - 2♠, a 6-3-2-2 bids one HCP lighter than a 5-4-2-2, for the 9th trump or the 6th card. On the phase 4 probes of 1♥ - 2♥ and 1♠ - 2♠, 6-3-2-2 hands bid game from 15–16 HCP and 5-4-2-2 hands from 17. After 1♠ - 3♣ (4+ spades), the 6th spade adds nothing: of 292 hands with 11–17 HCP, 5-4-2-2 and 6-3-2-2 bid 4♠ on half of the boards at 14 HCP alike (16 of 32 and 12 of 20) and on nearly all at 15 (16 of 18 and 7 of 8). So the 10th trump earns no point, and the 6th card earns one only if the 4-card side suit of a 5-4-2-2 earns one too. Only the single-hand ladders below differ, the 6-3-2-2 one bidding 4♠ from 14 HCP and the 5-4-2-2 one from 16.

• ♠AKJ987 ♥KQ9 ♦43 ♣52: 1♠ - 2♠ - 3♠ with 13 HCP. ♠AKJ98 ♥KQ98 ♦43 ♣52 passes.
• ♠AKQ98 ♥AQJ9 ♦43 ♣52: 1♠ - 3♣ - 4♠ with 16 HCP, and 1♠ - 2♠ - 4♠.

Not probed

• Whether the 6th card counts a length point, as the French help says, or only the 7th, as the English one says.
• Singleton and void values with 4+ trumps, and the opener’s distribution points before a fit is found.
• Fit points over a 1♥ or minor opening, and in competition.
• Honors in trumps, which the 2011 writeup counts as a support point. Of 4-4-3-2 responders to 1♠ with 9 HCP, 8 of 8 with 3+ HCP in spades bid 3♦, against 1 of 7 with less: too few boards for a rule.
• Whether a 4-3-3-3 responder leaves out the 9th trump or loses a point for its flat shape.
• The adjustments in other hands than balanced ones at the edges of the 1NT range and 5-4-3-1 ones with 10–11 HCP.
• The 14 HCP 1NT openings: 5 of 300 boards are too few for a rule.

Leads and signals

Wbridge5 defends by count. Its help file says so for the first seven tricks, and the probes below confirm it for the opening lead and for the first card it plays from each suit, whether it follows, discards or ruffs. A high card followed by a lower one (high-low) shows an even number of cards. The lowest card shows an odd number.

The probes played each deal over the Table Manager protocol, to trick 1 unless a section says otherwise, with nobody vulnerable and the program’s default card play options: signals on for the defense, 4th-best leads against notrump on, and Vinje off. The options are in the [WBR5] section of WBRIDGE5.INI, not with the bidding conventions in [Ench]. Hands below show the led or followed suit; x is any spot below the 8.

Count signals

These probes gave North the ace and king of a suit and had North lead the ace, with dummy playing low. Wbridge5 followed with:

• Odd number of cards: the lowest card, 261 of 270 times outside the trump suit and 156 of 157 in it.
• Even number: a high card, chosen so it cannot be mistaken for the lowest:
  • the highest spot below the 8 that is not the lowest card, e.g. 7 from J874 or 6 from 8654 (215 times);
  • with no such spot, the 8, e.g. from J1085 or 10987 (59 times);
  • with only an honor or the 9 above the lowest card, usually the 9 or 10 (50 of 68), with the jack about half the time (20 of 32), but almost never the queen. From Qx or QJ9x it plays low (25 of 27).

The rule is the same against notrump (385 deals) and in a side suit against 4♠ (365 deals). Under partner’s ace, it sometimes plays an honor from a sequence instead, such as the queen from QJ109xx.

Following in the trump suit is also count, not Vinje: the shape of the rest of the hand does not matter. Wbridge5 is stingier with high trumps, though. With only the 10, jack, or queen above its lowest trump, it played low 48 of 49 times. The 9 still signals (13 of 19), the 8 usually (13 of 17), and a spot below the 8 always (89 times).

Vinje, which shows the hand’s pattern with the trump card, is an option in the Options menu. It has no WBRIDGE5.INI key, so its effect was not probed.

Later tricks

These probes played on to trick 8 or 12. The probe script played declarer, dummy and partner by a fixed rule: lead a suit Wbridge5 was void in, else the top of the longest suit, and win as cheaply as possible. South held 0–9 HCP and defended 3NT or 4♠, often void in a suit to force discards and ruffs.

The first card Wbridge5 plays from a suit is a count signal, by the same rule as under partner’s ace. In tricks 2–7:

The even column leaves out holdings with only an honor or the 9 above the lowest card.

• Discards are count, not always the smallest card as the help file says: the 7 from J743, the 6 from 8642, but the 2 from A9532. Which suit it discards from follows no simple rule of length or strength.
• Ruffs show trump count: the 8 from Q1086 or the 6 from J652, but the 2 from J9732.
• Later cards in the suit are usually the lowest, completing a high-low after a high spot 173 of 181 times, and 263 of 333 times after a low one.
• After trick 7, the help file’s limit, few first cards are left. They still looked like count: the lowest from odd 25 of 28 times, a high spot from even 11 of 19.
• Winning a trick, it plays the lowest of touching cards (44 of 45).

Suit preference

Wbridge5 gives count where many players signal suit preference.

• Under partner’s ace with dummy void in the suit against 4♠, it still gave count on 10 of 10 boards, and on 41 of 43 with a singleton in dummy.
• Partner leads for a ruff: partner led the top of a suit Wbridge5 was void in against 4♠. It ruffed dummy’s winner every time (63 boards), with the count card above, and returned clubs or diamonds about evenly after a high or a low trump. It discarded under partner’s winner 41 of 51 times, also a count card.

Opening lead against notrump

Wbridge5 leads a suit of 4 or more cards, unless partner bid a suit. Over 1NT - 3NT it led its longest suit 237 times and a shorter 4-card suit 29 times out of 266; it never led a suit shorter than 4. Over a passed 1NT, the same hands led the same card 228 times.

A 7-card KQ10 suit led the queen (KQ109873, KQ108632, 2 hands). A 4-card suit headed by the ace was led from the bottom, 4th best, like any other.

With the 4th-best option off (4_longueNS=0), 153 of 172 leads changed. The card follows the method against suit contracts below, and the suit changed too, on 103 boards.

Opening lead against suits

Wbridge5 likes short suits against suit contracts. Over 1♠ - 4♠ it led a singleton 27 times, a doubleton 75 times, and trumps 26 times out of 229.

The card is the count signal again:

• Doubleton: top (107 of 108 small doubletons), including Jx
• 3 cards: lowest, from xxx, Jxx, Qxx, Kxx, Q10x (43 of 48 small tripletons)
• 4 cards: the same high spot as when following: 6 from 8654 or Q654, 7 from J875, 8 from J983, but the 10 from 109xx
• 5 cards: lowest
• Touching honors: the top one: KQx, KQxxx, QJxx, J10x, AKx, AKxx, and the king from AK doubleton
• Interior sequence: the 10 from K109xx and Q109x
• An ace: led, not underled: Ax, Axx, Axxx, AQxx, AKJxx, AKQxxx

The help file adds that a king lead promises the queen and a queen lead the jack, except in partner’s suit.

Opening lead against slams

These probes dealt Wbridge5 0–9 HCP and compared the same hands against game and slam. Its leads are deterministic: rerunning 103 hands against 3NT and 4♠ repeated every lead. It changed the lead on 250 of 275 hands from 3NT to 6NT, and on 156 of 246 from 4♠ to 6♠.

Against 1NT - 6NT, the lead is passive. It led from a suit without an honor above the 10 on 180 of 275 hands, never a 4th best, and a suit of 4 or more only 96 times (always against 3NT). The card is the count lead against suits: top of a doubleton (xx 47, 10x 13, Jx 10), lowest from 3 (xxx 33), a high spot from 4 (xxxx 11), and the top of touching honors (J10xx, KQxxx, AKxx).

Against 1♠ - 6♠, it cashes an ace: 79 of the 121 hands with an ace led one, against 15 of 117 against 4♠, e.g. Axx, Axxx, A10xxx. It led fewer short suits than against 4♠ (singletons 20 and doubletons 38 of 253, against 35 and 87 of 248) and about as many trumps (19 against 24).

Doubled contracts

Partner doubled the final contract after the same auctions, with the same hands:

Partner’s suit

When North overcalled 2♥ and East-West reached 3NT or 4♠, Wbridge5 led a heart 72 of 74 times against 3NT and 137 of 167 times against 4♠. The card is the count lead: top of a doubleton, lowest from 3 (64 of 84), and a high spot from 4. It is readier to lead an honor than in its own suit: the king from Kxx or K10xx, and the queen from Q10xx or Qxxxx, now and then.

Not probed

• The help file’s limit of seven tricks: few first cards from a suit come later
• Attitude signals, and Wbridge5’s own suit-preference card when it gives partner a ruff: it picks its own leads, so the spot cannot be forced
• How Wbridge5 reads partner’s signals: the probe script’s partner signals nothing
• Defense against a sensible declarer: the scripted declarer cashes its long suits and leads Wbridge5’s void. Against 4♠, Wbridge5 sometimes hung computing its play after such a line.
• Leads by a passed hand
• Leads from AKQ against notrump, and from AK doubleton against notrump
• Vinje, and how Wbridge5 reads a human partner’s cards with the Signals option on

Glossary

Constructive 1NT

The 1NT response is constructive in 1♣ - 1NT or after an overcall. Such 1NT requires 7⁺–10 HCP, balanced distribution, and a stopper in the adverse suit if the overcall shows one suit. This response still denies a biddable major suit. See 1♣ openings and responder’s calls over an overcall.

Delayed raise

A delayed raise shows game-forcing values by intentional violation of contract seeking rules. Such a raise must be at least 3-level to leave 2-level raises as natural suit preference. If a delayed raise is under game in an already game-forcing auction, the raise starts a slam try. See slam bidding after 1♣♦.

• 1♣ - 1♥ - 1NT - 3♣: This is a delayed raise. With an invitational hand, responder bids Roudy 2♣ instead.
• 1♣ - 1♥ - 2♣ - 3♣: This is a usual invitational raise because the fit may be newly found.
• 1♦ - 2♣ - 2NT - 3♦: This is a delayed raise showing slam interest.
• 1♦ - 2♣ - 2♦ - 4♦: This is a delayed raise showing slam interest.
• 1♠ - 2♣ - 2♠ - 4♠: This is a normal delayed raise showing real values, freeing 1♠ - 4♠ as a preempt.
• 1♠ - 2♣ - 2♠ - 3♠: This is a delayed raise showing slam interest because minimum is shown by 4♠.

Dustbin 1NT

The 1NT response in 1♦♥♠ - 1NT is dustbin, which shows a constructive 1NT or 6–10 points without another suitable call. It may hide a suit below the opening. See 1♦ openings and semiforcing 1NT.

Garbage Stayman

A legitimized psychic Stayman with a weak 3–4♠, 3–4♥, 4–5♦, 0–1♣. Responder passes opener’s most frequent rebids viz 2♦, 2♥, 2♠. See Stayman.

Lebensohl

Lebensohl is a conventional puppet bid 2NT after an intervened 1NT opening. This convention is also applied after a takeout double over an opponent weak 2. Usually the captain bids 3♣ relay and the puppet then rebids at 3-level.

Wbridge5’s Lebensohl over 1NT shows invitational values and may be a 4-card suit.

Puppet bid

A puppet bid is technically a relay but conceptually makes the bidder puppet instead of captain. The puppet forces or semiforces the captain to bid a relay.

If the captain has other options than the relay, the puppet bid is called a marionette. Examples are Lebensohl 2NT and the puppet special 2NT.

Relay

A relay is a conventional asking bid. The relayer, who bids the relay, becomes the captain. The captain provides little information and makes the final decision. The captain’s partner is the puppet, who describes hand when the captain asks. Examples are Stayman, RKCB and Roudy.

Roudy

Roudy (aka Roudi) is a club relay to ask notrump bidder’s strength and length of captain’s suit. The puppet answers artificially in short-long-long-short coding. This convention is in place of Checkback Stayman.

The short answers indicate the minimum length, 2 cards for opener’s notrump rebid, 3 cards for a puppet special 2NT.

Originally, this convention is 1x - 1y - 1NT - 2♣. Wbridge5 generalizes it to some auctions ending in 2NT - 3♣.

• 1x - y - 2NT - 3♣, where y is a new suit other than clubs
• 1M - 2NT - 3♣

See second responses, constructive rebids and forcing 2/1.

Semiforcing 1NT

The 1NT response to a major opening is semiforcing. The actual convention is opener’s 2♣, which is biddable with only 3 clubs if RHO did not overcall.

The 1NT is still semiforcing even if the major opening is intervened, i.e. such intervention only affects responder.

SJS

Strong jump shift.

Strong jump shift

Jump to a new suit over 1-of-a-suit opening in a constructive auction, showing 17+ points and 4+ cards. Wbridge5 SJS is more aggressive than Soloway jump shift. See slam bidding after 1♣♦.

Side suit restriction like Soloway only applies to 3♣♦ because 2/1 better handles the side suit. Bergen raise is also employed in Wbridge5, so the only Soloway-restricted jump shift is 1♦ - 3♣, but Soloway rebids are still never used.

Systems on

Wbridge5 reuses a structure wherever the auction resembles the one it was built for. An interference that leaves the needed space, or a rebid that shows the same hand as an opening, keeps the same continuations.

• 2♣ - 2♦ - 2NT, 2♦ - 2♥ - 2NT and 2♦ - 2♠ - 2NT: as after a 2NT opening, with responder’s ranges shifted for opener’s extra strength.
• 2♦ (X): the ace-showing responses stand; Pass is new.
• 1NT - 2♣ (X), 1NT - 2♣ (2♦), 1NT - 2♠ (X) and 1NT - 3♣ (X): opener answers as if undisturbed, as far as the space allows.
• 1m (1x) X: opener rebids as if responder had bid the major the double shows.
• Weak 2♥ (X) and (2♠): raises, the 2NT ask and splinters keep their meanings.
• 4NT (X): RKCB answers as if undisturbed.
• (1y) 1NT, also in the balancing seat: advancer bids as over a 1NT opening, except where a transfer or Stayman would name the opponents’ suit. (1♥) 1NT (2♥) is as 1NT (2♥) without the cooperative double.
• (2♥) 2NT: advancer bids as over a 2NT opening.
• (1♣) 2♥ and other weak jump overcalls: advancer bids as over a weak two opening.
• (1y) X (XX) and (1y) P (P) X: advancer bids as after (1y) X (P); after the redouble, Pass is new.

Openings

A hand with 12+ HCP is sufficient for an opening. With 10–11 HCP, open if HCP plus the lengths of the two longest suits reach 20, the rule of 20. Probing Wbridge5 5.12 shows this fits light openings better than counting points: it always opens at 21 and about half the time at 20, occasionally at 19 with a 7-card suit too poor for a preempt. If both hands in a pair are opening hands, they can probably make a game contract. Therefore, Wbridge5 opens every opening hand to prevent a pass out.

Moreover, some hands with good distribution but poor values are suitable for an opening as well. These openings are preemptive, which focus on disturbing opponents from bidding a good contract. Criteria for these openings depend on vulnerability and seat, so there is a separate article to describe them.

Alertable openings

These conventional openings are unexpected for a random bridge player. The game-forcing 2♦ is standard in France but unexpected outside. The standard meaning of 3NT is a strong balanced hand.

One-of-a-suit openings

Wbridge5 bids 1 of a suit with an opening hand ineligible for a strong opening. Opening in a major requires 5+ cards, 1♦ for 4+ cards, 1♣ for 3+ cards. With the special shape 4=4=3=2, it opens 1♦ as a fallback. If opener finds more than one eligible suit, bid the longest suit. If more than one eligible suit is equally long, bid the highest suit.

Do not consider suit quality. In bridge, quantity is more important than quality.

• ♠10 ♥1054 ♦KJ52 ♣AKJ97: Open 1♣ because clubs is the longer eligible suit.
• ♠J9864 ♥A8654 ♦A ♣KJ: Open 1♠ because spades is the higher eligible suit.
• ♠AQ73 ♥Q1087 ♦A862 ♣K: Open 1♦ because diamonds is the only eligible suit.
• ♠AK74 ♥AJ54 ♦J107 ♣72: Open 1♦ because no suit is eligible.

Strong notrump openings

The strong notrumps alleviate burden of suit openings. Balanced and semibalanced hands with specific strength are opened in notrump.

The 1NT opening also allows pattern 5-4-2-2 or 6-3-2-2 led by a minor. With 12–14 or 18–19 HCP, Wbridge5 opens 1 of a suit. Probing Wbridge5 5.12 shows that hand evaluation blurs the top of the 1NT range: 189 of 258 balanced hands with 17 HCP opened 1NT, and 76 of 265 with 18 HCP, fewer with more aces, 10s, or a doubleton. With 5-4-2-2, 12 of 42 hands opened 1NT at 17 HCP and none of 35 at 18. The bottom is firm: all 300 hands with 15 HCP, 2–4 cards in each major, and 2–5 in each minor opened 1NT, and 5 of 300 such hands with 14 HCP. Above, 2 of 53 balanced 19 HCP hands opened 2NT. A simple notrump rebid stands for weak notrump; a jump notrump rebid shows a hand between 1NT and 2NT openings.

• ♠54 ♥A863 ♦AQ986 ♣AJ: Open 1NT. Although this hand is not balanced, it is acceptable.
• ♠K9 ♥AKJ84 ♦KJ92 ♣76: Open 1♥. Always open the major with a major-dominant non-balanced hand.
• ♠A95 ♥KQ10 ♦AKJ6 ♣K102: Open 2NT.
• ♠A6 ♥KQ3 ♦K75 ♣AK987: Open 1♣. This hand is too weak for 2NT but too strong for 1NT.

Strong 2♣ & 2♦ openings

The strong 2♣ shows two kinds of invitational hands. The 2♣ is a limit bid, so the responder becomes the captain.

• 21–23 points unsuitable for a 2NT opening. Probing Wbridge5 5.12 shows that a 4-loser hand with fewer points opens 1 of a suit.
• 22–23 HCP, 2–4 cards in each major, 2–5 cards in each minor.

The strong 2♦ shows a game-forcing hand, stronger than 2♣.

What to bid with a big hand

There are three openings describing a hand with 21+ points or 20+ HCP, viz. 2NT, 2♣, and 2♦. This section is easier to follow after the continuations after 2NT, 2♣, and 2♦.

The chance to open 2♦ is slim. Actually 2♦ is a dustbin for hands way too strong, clarifying other bids for hands with 21–23 points. With 24+ points or 24+ HCP, Wbridge5 opens 2♦. Losers only break ties: 3-loser hands open 1 of a suit, 2♣, or 2♦ alike.

Probing Wbridge5 5.12 shows that the choice does not depend on seat or vulnerability. The same 300 hands with 19–26 HCP opened 2NT 65 times, 2♣ 74 times, and 2♦ 47 times, each hand making the same opening in all four seats and when both vulnerable. So did 300 balanced hands with 21–24 HCP in the 1st, 3rd, and 4th seats. See later seats in the 2♦ chapter.

The frequent rebids of 2♣ openings are 2♥ through 3♦. The 2NT rebid describes a notrump hand stronger than 2NT opening. The majors promise 5+ cards, minors 6+. Therefore, hands with 5-card major, 6-card minor, or 2NT distribution are noncontroversial.

The controversial hands are hands with a singleton or a void but no 5-card major nor 6-card minor. These patterns are 4-4-4-1, 5-4-3-1, and 5-4-4-0.

If the singleton in 4-4-4-1 is an ace or a king, take this hand as notrump distribution. Bid 1 of the minor suit for the other controversial hands. A wrong 1♦ is much easier to play than a wrong 3NT.

• ♠AKQ108 ♥J ♦AK1064 ♣K2: Open 2♣ and prepare to rebid 2♠.
• ♠K2 ♥A8 ♦AK1092 ♣AQ104: Open 2♣ and prepare to rebid 2NT.
• ♠K ♥AQ76 ♦AK65 ♣KQ104: Open 2NT. A partially stopped 4-4-4-1 is deemed as a notrump distribution.
• ♠Q1064 ♥AK6 ♦Q ♣AKQ52: Open 1♣ because this hand is controversial.
• ♠AKJ6 ♥A93 ♦K ♣AKQJ9: Open 2♦ with such a blockbuster. There is no controversy for a blockbuster, is there?

Suit openings from 2♥ on

See preemptive openings for the first 3 seats, balancing openings for the 4th seat.

Gambling 3NT

Gambling 3NT shows a 7+-card minor led by AKQ with no stopper in the side suits. This is a pass-or-correct bid where responder passes with 2 stopped suits.

• ♠642 ♥K ♦AKQ9652 ♣98: Open 3NT. Singleton king is no stopper.
• ♠642 ♥9 ♦AKQ9652 ♣K8: Open 1♦. Kx is half stopper.

Unusual 4NT

Unusual 4NT shows 6+ cards in each minor.

Not probed

• The 2♣ and 2NT openings in the 2nd, 3rd, and 4th seats on hands outside the 19–26 HCP set (all four seats) and the balanced 21–24 HCP set (1st, 3rd, and 4th seats).
• The gambling 3NT and the 4NT when vulnerable, seen on 1 and 10 boards.
• The gambling 3NT in the 2nd and 3rd seats.

Preemptive openings

Preemptive bids are bids higher than usual to aggressively reach a contract, avoiding defending. A preemptive opening shows < 12 HCP, which encourages reaching a suit contract and discourages reaching a notrump contract or defending.

Preemptive openings are available to the first three seats only, where there is still an opponent to block. The 3rd seat can make the most aggressive openings because the partner has passed.

Weak 2s

The weak 2s require 6+ cards in general, but 5 cards is accepted for the 3rd seat unless vulnerability is unfavorable. If non-vulnerable, the first two seats can also open a weak 2 with AKxxx or AQJxx in a 5-3-3-2 hand. The strength requirements are as follows.

In the first 2 seats, pass with 4+ cards in the other major. This prevents losing a 4-4 fit if partner has an opening hand.

• Vulnerable: 9+
• Not vulnerable: 7+

Probing Wbridge5 5.12 shows that the 1st and 2nd seats open alike: 300 hands with 5–7 hearts drew the same calls in both seats at all four vulnerabilities, as did 300 hands with 6–8 clubs at none and unfavorable. Mostly only Wbridge5’s own vulnerability counts. On 300 random hands with 4–11 HCP, favorable vulnerability opened exactly as none vulnerable, and both vulnerable exactly as unfavorable. With 5–7 hearts and 3–11 HCP, though, 5 of 300 hands opened a step higher at favorable than at none, and 7 of 300 at both vulnerable than at unfavorable. For example, ♠J9 ♥Q98653 ♦K76 ♣72 passes at none but opens 2♥ at favorable. With 6 hearts and 3–10 HCP, Wbridge5 opened 2♥ on 51 of 75 hands from 4 HCP when not vulnerable, but on 32 from 6 HCP when vulnerable. The 5-card weak 2s, e.g. ♠54 ♥KQJ97 ♦Q87 ♣1042 and ♠92 ♥AK872 ♦843 ♣976, all became passes when vulnerable. Spades behave the same: all nine 5-card 2♠ openings among 300 hands with 5–7 spades became passes when vulnerable, and the 6-card 2♠ fell from 41 of 58 hands to 31.

Weak 2s in the 3rd seat

In the 3rd seat both sides’ vulnerability counts. With 5–7 hearts and 3–11 HCP, 300 boards per vulnerability:

At unfavorable vulnerability, the 3rd seat also passes most of the light 1-level openings: with 5 hearts and 10–11 HCP, it opened 1♥ on 20 of 62 hands and passed the rest, where none vulnerable opened 1♥ or 2♥ on all but 4. At favorable vulnerability, those hands opened 2♥ on 38 boards and 1♥ on 23.

Preemptive 3s

Opening 3 of a suit promises 6+ cards with further requirements.

First 2 seats

If there are only 6 cards in the suit, it shall be no weaker than KJ10xxx if minor or KQ10xxx if major. The required strength is 2 more points than weak 2.

• Vulnerable: 11+, 8+ HCP
• Not vulnerable: 9+

As with weak 2s, favorable vulnerability opens as none vulnerable in the 1st seat. With 6 clubs and 3–10 HCP, Wbridge5 opened 3♣ on 46 of 200 hands (7–10 HCP) when not vulnerable and on 17 (8–10 HCP) when vulnerable. With 7–8 clubs it opened 3♣ on 49 of 62 hands from 5 HCP, and on 37 when vulnerable. A 7-card major drops a level when vulnerable: 4♥ needed 10+ HCP instead of 7+, and 5–6 HCP opened 2♥ instead of 3♥. Diamonds behave as clubs: with 6 diamonds and 3–10 HCP, 3♦ came on 50 of 193 hands (7–10 HCP) when not vulnerable and on 17 (8–10 HCP) when vulnerable. With 7 diamonds it came on 47 of 58 hands from 5 HCP, and on 36 from 6 HCP when vulnerable.

The 3rd seat

Quality of a 6-card minor can be as weak as KJxxxx in the 3rd seat, but no weaker for a major because a rubbish major opens a weak 2 instead. There are no more requirements on defensive values because the partnership will seldom have enough values for 3NT.

• Unfavorable: 9+
• Both vulnerable: 8+
• None vulnerable: 7+
• Favorable: 6+. A 6-card rubbish minor is acceptable here.

Probing Wbridge5 5.12 confirms the order. With 6 clubs and 3–10 HCP, the 3rd seat opened 3♣ on 154 of 206 hands at favorable vulnerability (from 4 HCP), 86 at none vulnerable (from 4 HCP), 66 at both vulnerable (from 5 HCP) and 17 at unfavorable (from 8 HCP). With 7 clubs, it opened 3♣ or 4♣ on 54 of 60 hands at favorable, 46 at none, 39 at both vulnerable and 31 at unfavorable. The 4♣ opening is natural here, with 7 clubs and 6–9 HCP, e.g. ♠Q2 ♥54 ♦86 ♣KQ109873 at favorable vulnerability.

Preemptive 4♥♠

Opening 4♥♠ promises 7+ cards. Only Wbridge5’s own vulnerability counts, and 4♥ opens alike in the first three seats. With 5–7 hearts and 3–11 HCP, 300 boards per vulnerability, the 2nd seat opened 4♥ on exactly the same hands as the 1st, and so did the 3rd seat but for ♠6 ♥KQJ10762 ♦- ♣A8653, which opened Namyats 4♣ in the first two seats, and ♠5 ♥AKJ652 ♦Q94 ♣J63, a 6-card 4♥ when not vulnerable. The 7-card 4♥♠ came on these hands:

As with weak 2s, favorable and both vulnerable each opened one hand a step higher than none and unfavorable: ♠9 ♥AJ107653 ♦Q105 ♣93 opened 4♥ at favorable but 3♥ at none, and ♠- ♥AQ98765 ♦J1095 ♣86 opened 4♥ at both vulnerable but 3♥ at unfavorable. At the top, 300 hands with 7–8 hearts and 11–16 HCP opened 4♥ on 25, all 7-card hands with 11–13 HCP; spades opened 4♠ on 31 such hands and two 8-card hands with 11 HCP. The rest opened 1♥♠, 2♣, Namyats or 3♥♠. These ran at none vulnerable only.

Preemptive 5♣♦

Opening 5♣♦ promises 8+ cards.

Namyats

Namyats uses 4♣ and 4♦ for strong 4♥ and 4♠ openers respectively. Besides criteria from 4♥♠ openings, there are further requirements for a Namyats opening.

• Suit quality: KQ10 or stronger if there are only 7 cards
• Strength: At most 5 losers

Responses and later rounds are in their own chapter.

Not probed

• Spade and minor preempts in the 1st seat at favorable and both vulnerable, beyond 300 random hands with 4–11 HCP. Only hearts had targeted hands at all four vulnerabilities.
• Spade and diamond preempts in the 2nd seat beyond 600 random hands at none vulnerable, and clubs there at favorable and both vulnerable.
• Spade and diamond preempts in the 3rd seat at any vulnerability but none, where 600 random hands were dealt. Hearts and clubs had targeted hands at all four vulnerabilities.
• Namyats and 5♣♦ in the 2nd and 3rd seats: the 2nd seat opened 4♣ with one hand and 5♣♦ with two; the 3rd seat never opened 5♣♦, and its 4♣♦ openings all held a long minor. 5♣♦ when vulnerable came up on 5 boards in all.
• The pass with 4+ cards in the other major: the targeted hands held 0–3, and the random hands held one weak hand with a 6-card major and 4 cards in the other.

Responses to preemptive openings

Responder to a preemptive opening seldom has a game, so most calls continue the preemption. Raises in this chapter are counted in support points (HCP plus shortness, see hand evaluation).

Weak 2♥♠

Raises follow the total number of trumps more than strength. Responder passes with 3-card support and a weak hand, raises to 3 with 4 cards, and bids game with 5. The 3-level raise is not invitational: it covers 2–14 HCP. With a strong hand, responder asks with 2NT instead.

Without a fit, responder passes up to about 15 HCP. For example, responder passes 2♥ with ♠K ♥K95 ♦AQJ95 ♣10865, 13 HCP. Vulnerability makes no visible difference to the raises: at favorable vulnerability, 2♥ - 3♥ was bid on 107 of 300 boards, against 100 with nobody vulnerable. Wbridge5 bid 3NT only with 16+ HCP and a doubleton in opener’s major.

Seat

Facing a 2nd-seat weak 2♥, responder is more active. With 12–15 HCP and 3-card support, it bids 2NT or 3♥ and never passes, where facing a 1st-seat weak 2♥ it passed half of such hands. It also bids 2NT with a doubleton more often. New suits still need about 12 HCP.

A passed hand never bid a new suit with 8–10 HCP and five spades over a 3rd-seat 2♥: it passed on all 265 boards.

Feature ask 2NT

Opener shows a minimum by rebidding the suit. With a maximum, opener shows shortness first, then an ace or king in a side suit, and bids 3NT with neither. The help file says only a void is shown, but Wbridge5 also shows a singleton.

The cheap 3♠ shows shortness, so a spade feature is not shown. Opener with only a spade feature bids 3NT.

The minimum ranges 6–8 HCP over 2♥ and 6–9 HCP over 2♠. A maximum is 11–14 points, so a singleton lifts some 6–7 HCP hands. Examples from 2♥ - 2NT:

• ♠Q83 ♥KQ8763 ♦63 ♣64: Bid 3♥, minimum.
• ♠- ♥AQ10864 ♦1092 ♣9732: Bid 3♠, a void with only 6 HCP.
• ♠J10 ♥K87653 ♦A52 ♣105: Bid 3♦, the ace.
• ♠92 ♥AQ10864 ♦Q64 ♣108: Bid 3NT, nothing to show.

Responder’s continuations after the answer were not probed.

Interference

Over a takeout double or a 2♠ overcall, the raises, 2NT, and splinters keep their meanings, systems on. Opener’s answers to 2NT under interference were not probed.

Without support, responder passes even with 16 HCP. The redouble does not look for a penalty.

Over a 3-level overcall, the double is still for penalty, and 4 of the opponents’ suit is a strong raise. Responder needs 3 cards to compete in opener’s suit.

A doubleton is not enough to raise over an overcall. Wbridge5 raised with a doubleton on only 2 of 600 boards.

Preemptive 3s

Responder raises to game with a major fit and 10+ HCP. A raise to 4 of a minor continues the preemption. New suits are natural and only seen over minors.

Probing Wbridge5 5.12 shows that a 3♣ opener answers 4NT as RKCB 0314 in clubs, counting the ♣K, on all 226 boards. So do 3♦♥♠ openers in their own suits, on all 559 boards, ignoring any void. For example, ♠Q2 ♥54 ♦86 ♣KQ109873 bids 5♦.

Over 3♥♠, responder passed 10–15 HCP hands without a fit. It bid 3NT on none of 600 boards and a new suit on one. Over 3♠, 4♥ was natural with seven hearts. Responses over a 2nd-seat 3♣ were the same as over a 1st-seat one.

Interference

Over a double, a redouble shows a good hand, not a penalty. Responder competes with 4-card support and a weak hand.

Over an overcall, the double is for penalty.

Gambling 3NT

The gambling 3NT shows a 7–8-card minor headed by AKQ. Probing found no side ace or king in any of 46 openings.

Responder can often tell opener’s minor. For example, with ♠76 ♥A76 ♦1097 ♣AKQ94, responder knows that opener holds diamonds and bids 6♦.

Opener corrected on all 58 boards.

Namyats

Responder does not bid the next step over Namyats. It signs off in opener’s major or asks with RKCB 4NT, usually with 14+ HCP.

Probing Wbridge5 5.12 shows the Namyats opener answering RKCB 0314 in its major, ignoring any void, on all 223 boards. For example, ♠97 ♥KQJ109862 ♦- ♣A75 bids 5♠ over 4♣ - 4NT.

4♥♠ and 5♣♦

Over 4♥♠, responder passes up to about 18 HCP and bids RKCB 4NT with slam interest. Probing Wbridge5 5.12 shows that a 4♥ opener answers it as RKCB 0314 on all 112 boards, ignoring any void, and a 4♠ opener on all 122. For example, ♠J32 ♥AKQJ1092 ♦753 ♣- bids 5♠.

Over 5♣♦, responder raises to 6 with slam values, usually 14+ HCP, although a quarter of 14+ HCP hands passed. The raise needs only a singleton in opener’s suit.

4NT

The 4NT opening shows 6-6 in the minors or longer. Responder bids the longer minor, at the 6-level with a good hand, usually 12+ HCP. With equal minors, responder chose either.

Not probed

• Rebids after a new suit by responder, and whether those new suits are forcing
• Responses to 3rd- and 4th-seat preempts other than those above
• Interference over 3NT and the 4- and 5-level openings
• Hands under 8 HCP after interference, so the lower ends of those ranges are open

Balancing openings

Balancing refers to making a non-pass call to prevent passing out. For an opening, this means opener is at the 4th seat.

Since there is no more opponent to preempt, aggressive preempts are pointless. Wbridge5 drops the gambling 3NT and Namyats in this seat. Probing Wbridge5 5.12 shows these openings from 3NT on.

A hand that opens 3NT in the first three seats opens 1♣ or 4♣ instead, and a Namyats hand opens 4 of its major. The 4NT opening is unchanged: all 150 probed 6-6 minor hands opened it, with 2–14 HCP.

• ♠63 ♥97 ♦9 ♣AKQJ10974: 1♣, though 3NT in 1st seat.
• ♠K5 ♥Q ♦72 ♣AK765432: 4♣, though 5♣ in 1st seat.
• ♠J ♥KQJ108732 ♦102 ♣A5: 4♥, though 4♣ in 1st seat.
• ♠KQJ10943 ♥- ♦KQ642 ♣5: 4♠, though 4♦ in 1st seat.

One-of-a-suit openings

A light opening in the 4th seat follows the rule of 15: open if HCP plus spades reach 15.

Weak 2s

The weak 2s are still preemptive, which shows < 12 HCP and 6+ cards. However, a balancing weak 2 shows more offensive values than other seats.

Probing Wbridge5 5.12 shows that vulnerability barely moves this floor. With 6 hearts, a balancing 2♥ came from 7 HCP up, mostly 9–10 HCP, at none vulnerable (23 boards) and at unfavorable (28 boards). At unfavorable vulnerability, 2 hands with 7 HCP passed instead, and 7 hands with 10–11 HCP bid 2♥ instead of 1♥, e.g. ♠KQ10 ♥KQJ753 ♦87 ♣32. On 300 boards with 5–7 hearts and 7–13 HCP, 12 calls changed. Favorable and both vulnerable were only probed on 40 boards each, and no call changed.

Why not play strong 2s for the balancing seat? Weak 2s greatly avoid shitty auctions like 1♥ - 1NT - 2♥ - 3♥ passed out.

Preemptive 3s

Opening 3 of a suit shows 7+ cards and requires opening offensive values (13+ points) but no opening defensive values (< 12 HCP). With a 7-card minor and 10+ HCP, open 1 of the minor instead.

Signoff 4♥ & 4♠

These two stay in the 4th seat because major games are so profitable. They now stand for 4♥ and 4♠ openings with 8–13 HCP, so opening values are allowed.

Not probed

• The balancing 2♠ with 6 spades: the targeted spade hands held 7+, and 4 of 600 random hands opened 2♠.
• Vulnerability: the hands with 5–7 hearts had 300 boards at unfavorable and 40 each at favorable and both vulnerable. The other 4th-seat openings were probed at none vulnerable only.

Natural 1♥♠

Modern bidding systems often require 5+ cards to open in a major. This is somewhat conventional because usually a 4-card suit is biddable in bridge, but this greatly improves search of 5-3 and 6-2 major fits.

Although minor openings are lower and more frequent, major openings are explained first because

1. Major openings are more symmetric where both require 5+ cards.
2. There are fewer mediocre exceptional bids which are difficult for beginners.
3. Some conventions designed for majors can also apply to minors.

Light openings

Opening a major at the last 2 seats requires only 11+ HCP and 5+ cards, or just 10 HCP with 5-5 shape.

Nevertheless, a weak 2 can be made with only 5 cards at a non-unfavorable 3rd seat. This phenomenon excludes Drury from the Wbridge5 bidding system because major openings at the 3rd seat are seldom light.

Probing Wbridge5 5.12 shows that at unfavorable vulnerability the 3rd seat is not light at all: with 5 hearts and 10–11 HCP it opened 1♥ on 20 of 62 hands and passed the rest. See 3rd-seat weak 2s.

Responses to 1♥

The 1NT response is a semiforcing dustbin, and new suits at the 2-level are forcing 2/1. The strength of the preemptive 4♥ depends on vulnerability.

Adjusted responses by a passed responder

Responses from a passed responder are no longer forcing because the previous pass has limited the strength. Some conventions are cancelled to make these bids passable.

Probing Wbridge5 5.12 shows that a passed responder still splinters with shortness, so the limit raise denies it.

Responses to 1♠

The 1NT response is a semiforcing dustbin, and new suits at the 2-level are forcing 2/1. The strength of the preemptive 4♠ depends on vulnerability.

Probing Wbridge5 5.12 shows that 3♥ over 1♠ is also a strong raise with 4 hearts. Of 300 hands with 4–5♠ and 17–24 HCP, 50 bid 3♥, all with exactly 4♥, 1–3 cards in each minor, and 17–22 HCP; for example, ♠AJT2 ♥KQ53 ♦AQ2 ♣Q8. Random hands add ♠AKQ2 ♥AQT8 ♦J7 ♣973 and ♠AQ63 ♥QT64 ♦AK7 ♣J8.

Adjusted responses by a passed responder

Responses from a passed responder are no longer forcing because the previous pass has limited the strength. Some conventions are cancelled to make these bids passable.

Preemptive raise to the 4-level

Such raise directly jumps to game, showing at most 8⁻ HCP and usually 5+ support. Its minimum strength is determined by vulnerability.

• Unfavorable: 10+
• Both vulnerable: 10+
• None vulnerable: 8+
• Favorable: 7+

Major raise structure

The 12 points are intentionally duplicated in this table. It is difficult to find clear-cut game-forcing hands with only points.

With a flat hand, 3-card support, and 6 or 11 HCP, Wbridge5 bids 1NT for better continuations.

Choice of new suit

1. Choose the longest suit.
2. To break a tie, bid the cheapest call for 4-4, the highest suit for 5-5 or above.

In the following examples, your partner opened 1♥ and you have not passed.

• ♠J1064 ♥A8 ♦A4 ♣108763: Bid 1♠. This hand is too weak to bid 2♣.
• ♠AK3 ♥K6 ♦J652 ♣AK53: Bid 2♣. Bid the cheapest call for 4-4.
• ♠Q9 ♥6 ♦Q9743 ♣AK942: Bid 2♦. Bid the highest suit for 5-5.
• ♠A103 ♥A953 ♦AQ9 ♣AK3: Bid 2♣. This hand is too strong for 3NT. Probing Wbridge5 5.12 shows a 3-card minor bid with such a blockbuster: 2♣ on 272 of 300 boards and 2♦ on the rest.

Special 2NT

The special 2NT shows

• Limit raise or better without slam interest (11–16 points, 3+ support).
• Somewhat balanced (2+ cards in every suit).

If responder has passed, this 2NT bid has given enough information for opener to sign off.

Puppet special 2NT

If responder has not passed yet, this 2NT bid is a puppet forcing opener to bid an artificial relay 3♣. Responder shows support and strength in the second round.

Probing Wbridge5 5.12 shows that opener splinters instead of relaying with 17+ points and a singleton or void. See constructive rebids.

The 3♥ response is also forcing to game because Bergen 3♦ already takes care of invitational hands.

This convention appears to be Wbridge5’s own, probably derived from Jacoby 2NT. It relieves the 2/1 structure of Wbridge5 in three ways.

• Special 2NT handles 3-card limit raise, freeing dustbin 1NT from forcing.
• Jacoby 2NT fits into special 2NT and serious 3NT, leaving no burden for other bids.
• Responder shows. Opener relays, hiding information from opponents.

Not probed

• The preemptive 4♠ raise by vulnerability: only the 4♥ raise was probed at all four vulnerabilities.
• Light 1♠ openings in the 3rd and 4th seats away from none vulnerable: only hearts were probed at the other vulnerabilities.
• The 3♥ response to 1♠ with 4♥ below 17 HCP (two random hands), and the auction after it.

Semiforcing 1NT

The 1NT response to a major opening is semiforcing. The semiforcing 1NT is a dustbin for hands with 5–10 HCP and no other available bid. However, with a flat hand, 3-card support, and exactly 6 or 11 HCP, Wbridge5 bids 1NT instead of direct support. Probing Wbridge5 5.12 shows that other 11 HCP hands bid a 2/1 instead.

In Wbridge5, the 1NT is more forcing than an American semiforcing 1NT.

• Opener always rebids 2♣ with 3 cards if balanced.
• A 4-card lower-ranking side suit is never passed by suit quality.

Flat raises

The 4-3-3 side suits make it awkward to play a suit contract. With a 6 or 11 HCP flat raise, Wbridge5 bids 1NT rather than raising. For example, ♠J72 ♥10654 ♦J83 ♣A75 and ♠Q64 ♥A852 ♦K96 ♣Q64 both bid 1NT over 1♠.

Such 1NT is a bet on opener’s usual rebidding. Opener’s rebid provides good continuations like forcing 1NT. Opener’s pass leads to a mediocre but acceptable result. To make the pass rare, Wbridge5 has opener rebid 2♣ with 3 clubs.

Flat weak raise

Responder aims to sign off in 2M.

With flat 6 HCP, simple support may lead to disastrous 1M - 2M - 3m - 3M. Since 2M is usually the best contract and 1NT is no worse than 3M, Wbridge5 bids 1NT and counts on opener not passing.

Flat limit raise

Responder invites a minimum opener in the next round.

The special 2NT enforces a major fit and never results in a notrump contract. The 1NT lets opener reconsider notrump contracts.

When does opener pass

As usual, opener passes when no bid describes. However, opener tries hard to bid, so there are only few hands left for the pass.

• Minimum balanced hands with doubleton clubs: The other 2/3 balanced hands are safely biddable.
• Flannery opening hands with no biddable minor: These 4=5=2=2 and 4=5=3=1 hands are inherently hard to bid.

Opener’s rebids

Choice of strain

• Notrump vs suit: Major > notrump > minor
• Original suit vs side suit: 7-card original suit > 4-card side suit > 6-card original suit > 3-card 2♣

After 1♥ - 1NT

Opener rebids by the choice of strain above. With 3 clubs, opener bids 2♣ rather than passing.

After 1♠ - 1NT

Over 1♠, opener can show either red suit at the 2-level.

Second responses to a 1♠ opener

These 1♠ continuations are mentioned first to derive 1♥ counterparts because this way is easier than vice versa. Both bids in 1♠ - 1NT contain more shapes than in 1♥ - 1NT. Derivation of 1♥ rules from 1♠ ones is simple generalization except opener’s reverse.

After 1♠ - 1NT - 2♣

A new suit is constructive. A jump to 3♠ is a flat limit raise.

After 1♠ - 1NT - 2♦

Responder can still show hearts, or a long club suit at the 3-level.

After 1♠ - 1NT - 2♥

A minor at the 3-level shows a long suit.

After 1♠ - 1NT - 2♠

Opener has shown 6+ spades, so responder raises with only 2–3 cards.

Second responses to a 1♥ opener

Most responses can be deduced from 1♠ continuations. This section lists only discrepancies. There are 2 sources of discrepancies, both related 2♠.

• Opener has reverse 2♠.
• Responder denied spades, which makes 2♠ good for a forcing convention.

Probing Wbridge5 5.12 shows that a ♠ stopper here is the ace or king.

After 1♥ - 1NT - 2♣

After 1♥ - 1NT - 2♦

After 1♥ - 1NT - 2♥

Comparison to other 1NT treatments

Wbridge5’s 1NT is semiforcing in a strict sense: after a minimum opening, the 2♣ rebid is more frequent than pass. After an American semiforcing 1NT, pass is still the most frequent call.

The following is analysis after a minimum opening.

Not probed

• The flat raise with 6 HCP: 4 random boards for an unpassed responder, where the flat 11 HCP raise had 300 targeted boards.
• Responder’s second call after opener’s 2NT, a 3-level rebid, or the reverse 1♥ - 1NT - 2♠.
• Opener’s rebids after a passed responder’s 1NT.
• Either side’s calls when the opponents double or bid after 1M - 1NT.

Forcing 2/1

The concept that 2/1 auctions should be forcing to game has been popular since 1990s. The world is gradually moving from standard to 2/1. Wbridge5 is also a move based on SEF, the French standard.

The 2/1 in Wbridge5 is Lawrence-style.

• The game force may be occasionally cancelled.
• Opener’s reverses and jumps require extra strength.

Wbridge5 counts distribution and length points, so a 2/1 may hold only 9–10 HCP with a long suit or shortness.

The 2/1 bids has low priority due to its ambiguity. Raises, 1NT, and fit-showing conventions are limit bids and show whether a fit is found. The 2/1 bids, unlimited and ambiguous about fit, can be viewed as natural relays.

The 2/1 responses

Probing Wbridge5 5.12 shows 3 criteria corresponding to the 3 kinds of games viz. major, notrump, and minor. Any met criterion makes a hand eligible for 2/1.

• Found major fit or 1♠ - 2♥, 12+ points
• 11+ HCP but no flat 11 HCP
• With long minor, 14+ points (but 13 points is enough for 1♥ - 2♦)

On 600 boards after 1♥ - P and 1♠ - P, every 2/1 but one met a criterion, and every hand without support that met one bid 2/1 unless it had a higher-priority call such as 1♠ or a strong jump shift. The exception was ♠3 ♥10952 ♦AJ108 ♣A743 bidding 2♣ over 1♠. With a flat 11 HCP and 3-card support, responder bids 1NT instead (203 of 216 boards over 1♠).

The thresholds match the maximum hands that pass the semiforcing 1NT, i.e. 13–14 HCP and usually 5-3=3=2. A 1♥ opener who passes 1NT may instead hold 4=5=3=1, which fits a 2♦ response better, so 1 fewer point is needed.

2♥ vs SJS 3♥

Both of them are unlimited. There are strict criteria on 3♥ because it consumes too much space. With 17+ points and 5+ hearts, bid 2♥ unless there are 7+ hearts and 0–2 spades.

Opener’s rebids

Responder bid a minor

Opener describes strength and shape naturally. Reverses and jumps show extra strength.

1♠ - 2♥

Opener can support with 3 cards, and such support is eager because hearts is also a major. Therefore, fit-showing bids are different from the previous section. Other bids, not showing a fit, are omitted for duplicate.

Wasted points removed, with a support but hard minimum (< 14 points), bid a fallback 2♠ or 2NT first to dissuade partner from searching slam.

Probing Wbridge5 5.12 shows 3♥ also covers minimum hands with 4-card support and no shortness.

The 2NT rebid with a 6-card major

Wbridge5 rebids 2NT with a 6-card major only when both of the following hold.

• Over 1♠ - 2♥♦
• Found heart fit or worse than ♠AQJ9xx

The 1♥ opener always rebids 2♥ with 6-card hearts lest 6-2 fit be lost. Over 1♠ - 2♣, always bid 2♠ with 6-card spades to make both 2♠ and 2NT specific: 2NT shows exactly 5 cards, 2♠ 6+.

If the trump suit is at least AQJ9xx, it is too good to play notrump. However, with a heart fit but too weak for a direct 4♥, opener may bid 2NT and reach 4♥ later.

Second responses

Responder no longer hides a major fit in this round. If responder bids notrump or a new suit below 3NT, no major fit is found as natural bidding goes.

Decisions to cancel the game force debut here. All of them are nonforcing bids below 3NT.

Opener rebid own suit or below

Opener showed a minimal (non-maximum) unbalanced hand. Rebidding the opened suit is the most frequent rebid overall. Note that 1♠ - 2♣ - 2♠ is the only circumstance where a 6th card is for sure.

In the following tables, x is responder’s suit and y is opener’s rebid suit.

Raises

There is enough space to bid weak and strong hands under game for safety and bidding space respectively. Here M is a major opener has bid, and m is a minor opener has bid. Over 1♥ - 2x - 2♥, the jump to 3♠ is a splinter.

Probing Wbridge5 5.12 shows it also bids 3♠ over 1♠ - 2♣ - 2♠ with a minimum and a doubleton, and it may pass 2y with < 14 HCP and a 6+ minor.

Others

With combined 28–30 HCP, it is often better to play 3NT than a suit game. Therefore, responder’s best bet with a balanced hand and some excessive strength is to sign off 3NT.

Over 1♠ - 2♥ - 2♠, 4♥ is to play and 3♥ is unlimited.

Opener rebid 2NT

The 2NT rebid shows 11–14 HCP, balanced or 5-4-2-2 where the 4-card suit is skipped. This rebid is the 2nd most frequent.

Most second responses are the same as if opener rebid the opened suit or below because 2NT is minimum. The following only describe differences.

The 2011 writeup treats this 4NT as plain Blackwood. Probing Wbridge5 5.12 shows responder bidding it with balanced 18–20 HCP over 1♥ - 2♣ - 2NT and 1♠ - 2♣♥ - 2NT, 13 boards in all. Opener answers it as Blackwood, counting aces only: 5♣ for 0 or 3, 5♦ for 1, 5♥ for 2 on all 243 boards probed over 1♥ - 2♣ - 2NT. The ♥K does not count, and opener never passed or bid 6NT. For example, ♠J53 ♥AJ532 ♦K94 ♣K10 bids 5♦, and ♠A43 ♥KJ987 ♦A9 ♣Q63 bids 5♥.

There are further considerations for responder to show a long suit, so they are described in details.

Responded 2♣

Because 2NT is weaker than a simple suit, 2 more points are needed to try slam.

Over 1♥ - 2♦ - 2NT

The 3♦ serves as a parachute because 1♥ - 2♦ may be extraordinary weak and based on distribution. Forcing hands go to 3♣.

Quantitative invitations are off as Roudy is superior by its low level.

Over 1♠ - 2♦ - 2NT

There is no clear line between 3♣ and 3♦. Bid 3♣ if there is need to know partner’s strength.

Over 1♠ - 2♥ - 2NT

A heart fit is found with 6+ cards, so 3♥ is a slam try according to the principle of fast arrival.

Not probed

• Responder’s second call after opener’s reverses, jumps and 3-level rebids, except 1♠ - 2♥ - 3♥.
• Opener’s answer to 4NT after the other 2NT rebids: only 1♥ - 2♣ - 2NT - 4NT was probed.

Constructive rebids

This chapter covers the uncontested auctions after 1♥♠ outside the semiforcing 1NT and forcing 2/1: 1♥ - 1♠, the raises, and the strong responses. The responses themselves are in the parent chapter.

The ranges come from probing Wbridge5 5.12 on about 250 boards per auction. Ranges are in points, i.e. HCP plus distribution and length points, except where marked HCP.

After 1♥ - 1♠

Opener raises spades only with 4 cards. With 3 spades and a minimum, opener rebids 1NT. There is no reverse because 2♠ is the raise, so opener shows extra strength by jumping.

Wbridge5 rebids 2NT with any balanced 18–21 HCP and never rebids 3NT here. For example, ♠K54 ♥AK643 ♦AK3 ♣Q9 rebids 2NT. With ♠A1042 ♥AKJ75 ♦7 ♣A97, opener jumps to 3♠ rather than splintering, but ♠A976 ♥AKJ952 ♦A96 ♣- bids a 4♣ splinter.

Responder’s rebids after 1NT

Responder’s 2♣ is Roudy, which asks about spade support and strength. It needs 5+ spades. With 4 spades, responder bids notrump directly.

For example, ♠AKQ1093 ♥J10 ♦Q53 ♣104 bids 2♣. Opener answers in the short-long-long-short code. A minimum has 11–13 HCP and a maximum has 13–14 HCP.

Responder’s rebids after a new suit

The fourth suit 2♦ is forcing.

The 4♣ row comes from 4 boards. The 2011 writeup says that only a fourth suit at the 2-level in a minor is forcing, so 1♥ - 1♠ - 2♦ - 3♣ would be natural. That auction was not probed.

Simple raise

Opener’s game tries are natural. A new suit shows 4+ cards and invites game, and a jump to the 4-level is a splinter.

The 3♠ row comes from 3 boards. Opener also bid 2NT on 3 boards with 15 points and 5-3-3-2.

For example, ♠A72 ♥AQJ98 ♦K762 ♣8 makes a 3♦ game try over 1♥ - 2♥. With ♠K82 ♥AKJ63 ♦AK82 ♣6, opener bids 4♥.

Responder accepts a game try with 9+ HCP, or with 7–8 HCP and 5+ cards in the asking suit. After 1♥ - 2♥ - 3♣, ♠A42 ♥K52 ♦8654 ♣Q43 bids 4♥. The 2011 writeup’s rule, 8+ points or a double fit, fits the data.

Bergen raises

Opener signs off or bids game. Wbridge5 never control-bids over the mixed raise 3♣, even with 20+ points.

Over the limit raise, the game threshold drops to 14 points. Only 1♥ - 3♦ was probed.

The 2011 writeup has opener control-bid with 20–21 over 3♣ and with 19–21 over 3♦. Over 3♦, Wbridge5 makes a 3♠ slam try with 17+ points.

After 1M - 3♣ - 3M, responder passes. The 2011 writeup says that responder bids game with 5 trumps, but Wbridge5 passed on 92 of 97 boards with 5 hearts and 7–9 HCP.

Special 2NT

Unpassed responder

Opener relays with almost every hand, but splinters with 17+ points and shortness. The relay continuations are in the parent chapter.

Over 1♥, the splinters are 3♠, 4♣, and 4♦. Over 1♠, they are 4♣, 4♦, and 4♥. For example, ♠K82 ♥AKJ63 ♦AK82 ♣6 bids 4♣ over 1♥ - 2NT. The 2011 writeup has these jumps as control bids, but every probed splinter held a singleton or void in the bid suit.

Passed responder

A passed responder’s 2NT is a limit raise. Opener signs off at the 3- or 4-level, or tries for slam.

The 3♠ row comes from 7 boards, and every hand held the ♠A or ♠K. The 3NT row comes from 4 boards.

Fit-showing jumps

Opener may pass a fit-showing jump with a minimum and a fit for responder’s suit. Over 2♠, opener can also choose spades as trumps.

For example, ♠J53 ♥AJ532 ♦K94 ♣K10 passes 2♠.

Opener passed 3♣ on 3 boards, each with 11 HCP and 4–5 clubs. On 3 more boards, opener bid 4♣ with 18–19 HCP.

Strong jump shift 1♥ - 2♠

Opener describes the hand naturally. 2NT shows a minimum balanced hand.

The 2011 writeup lists two 2NT rows here, 12–17 and 18–21 HCP. Wbridge5 bids 3NT with the strong balanced hand.

Serious 3NT and splinters

Over serious 3NT or a splinter, opener signs off with a minimum and control-bids otherwise. A control is an ace, a king, a singleton, or a void. The two auctions probed were 1♥ - 3NT and 1♥ - 3♠.

Not probed

• Responder’s rebids after 1♥ - 1♠ - 2♦, 2♥, 2♠ or a jump, including 1♥ - 1♠ - 2♦ - 3♣.
• Opener’s rebid after the fourth suit 1♥ - 1♠ - 2♣ - 2♦, and responder’s call after the Roudy answers.
• Responder’s call after game tries other than 1♥ - 2♥ - 3♣, and after 1♠ - 3♣ - 3♠.
• Opener’s rebids after the limit raise 1♠ - 3♦, the preemptive raise 1M - 3M, the strong jump shift 1♠ - 3♥, the serious 1♠ - 3NT, and the splinters other than 1♥ - 3♠.
• P - 1♠ - 2NT, and the fit-showing jumps other than P - 1♥ - 2♠ and P - 1♠ - 3♣.

Competitive rebids

This chapter covers opener’s rebids after 1♥♠ when the opponents bid, and responder’s calls over an overcall. Ranges are in points, except where marked HCP.

RHO bids over the response

Support doubles

Over 1♥ - 1♠, a double or redouble by opener shows exactly 3 spades at any strength. A raise still shows 4 spades.

For example, ♠J53 ♥AJ532 ♦K94 ♣K10 redoubles over 1♥ - 1♠ (X), and ♠A43 ♥KJ987 ♦A9 ♣Q63 doubles over 1♥ - 1♠ (2♣). With ♠87 ♥AQ863 ♦K85 ♣K103, opener passes the double.

The 2011 writeup limits the support double to 14–21 points. Wbridge5 doubles or redoubles with 3 spades even at 11 HCP.

At the 3-level the support double needs extra values. A minimum opener with 3 spades passes.

Of the 96 hands with 3 spades, 56 passed with 11–15 HCP and 28 doubled with 14–19 HCP. For example, ♠K82 ♥AKJ63 ♦AK82 ♣6 doubles, but ♠J53 ♥AJ532 ♦K94 ♣K10 passes. Opener bid 4♣ on 2 boards, each with 4 spades and a club void. The probe gave opener 2–4 spades.

Simple raise

When RHO doubles the raise, opener passes with exactly 5 trumps and no interest in game.

For example, ♠QJ985 ♥A4 ♦K108 ♣KJ4 passes and ♠KQJ83 ♥A ♦Q972 ♣A104 redoubles. The 2011 writeup has XX as an invitation with 17–18 and 4♠ with 19–21, but Wbridge5 redoubles with any strong hand.

Over an overcall, opener competes to the 3-level or bids game.

Wbridge5 never doubled here. Opener bid 2NT on 4 boards. Five of the six 3♠ hands held the ♠A or ♠K.

Bergen raise

Wbridge5 never passed or redoubled.

2/1 overcalled

Opener’s rebids stay natural. The pass is forcing because the 2/1 is forcing to game. Opener passes with a minimum and no stopper.

Opener doubled on 3 boards, each with a singleton heart, 4 diamonds, and 3 clubs.

LHO doubles

After 1♥ (X) 1♠ (2♣), Wbridge5 plays systems on and uses the same support double as in 1♥ - 1♠ (2♣). The two auctions got the same call on 233 of 251 boards. On the other 18 boards, opener bid more cautiously after the double, e.g. 2NT instead of 3NT, or 2♥ instead of 2♦ with 6 hearts.

Responder passes

If 1♥ (X) is passed back to opener, the contract is 1♥ doubled. Opener passes with long hearts and runs only to a 4-card spade suit or a 5-card minor.

If the doubler’s partner bids 1♠, opener rebids naturally.

Truscott 2NT

Opener signs off at the 3-level or bids game. A new suit is a slam try.

Opener bid 4♣ on 3 boards with 18–19 HCP and a club control.

Weak jump shift

Over 1♥ (X) 2♠, opener raises with only 2 spades.

Opener reopens

After 1♥ - P (X), opener rebids the same way as in 1♥ (X) P (P), except that opener now rebids 6+ hearts. For example, ♠104 ♥KQJ10653 ♦A109 ♣A rebids 3♥ here but passes 1♥ (X) P (P).

The 2♠ row comes from 4 boards. Wbridge5 never doubled 2♣.

LHO overcalls

Responder’s calls

Responder’s double is negative. Over 1♠ or 2♥ it shows both minors and exactly 2 cards in opener’s major. Over 2♣ it shows spades. Responder never makes a penalty double of a suit overcall. With length in LHO’s suit, responder passes. Unless marked, these probes gave responder 0–3 cards in opener’s major.

All 12 doubles had 2 hearts and 4-4 or longer in the minors. Another 11 hands of that shape passed with 5–10 HCP. For example, ♠J104 ♥QJ ♦KQ65 ♣J982 doubles.

With 4+ hearts, responder raises by length and strength. The raise to game is preemptive, and the jumps in a new suit are splinters. These rows come from 300 boards with 4+♥ and 0–10 HCP, none vulnerable.

At unfavorable vulnerability the 5-card raise to game needs more. With 5 hearts, 4♥ needed 7+ HCP, and 13 hands with 5–7 HCP raised to 2♥ or 3♥ instead, e.g. ♠T9 ♥K10943 ♦543 ♣A96 bids 4♥ at none vulnerable and 3♥ at unfavorable. Of the other raises, only one 6-card 3♥ changed, to 4♥.

The double comes from 6 boards, for example ♠73 ♥52 ♦K942 ♣AKQ82. The 2011 writeup has the same double from 10 points.

The double usually shows exactly 4 spades. With 5 spades responder doubles only with 6–9 HCP, and bids 2♠ with more. For example, ♠KQ54 ♥K2 ♦KQ876 ♣107 doubles.

The 2011 writeup has this double for penalty. Probing Wbridge5 5.12 shows a takeout double on 4 boards, for example ♠K10 ♥84 ♦Q8653 ♣AQ104. The 71 hands with 4+ hearts passed, up to 16 HCP. Responder also bid 4NT on 12 boards: 5 with both minors and 7 with 3 spades and 12–15 HCP.

Responder doubled 192 of the 227 hands with 8+ HCP. Most of the rest raised hearts.

Over Precise Michaels

The opponents’ 3♣ over 1♥ is a Precise Michaels bid for spades and diamonds, because the opponents play Wbridge5’s own defaults. Responder never doubled on 300 boards, even with 4 spades and 13 HCP. Responder’s calls over the other two-suiters, such as 1♥ (2♥), are in Two-suited overcalls.

Opener’s rebids after a negative double

The 2011 writeup has 2NT with 18–19 HCP and 3NT with 20+. Wbridge5 never bid 2NT or cuebid 2♠, and it jumped to 3NT with 16–19 HCP.

For example, ♠QJ985 ♥A4 ♦K108 ♣KJ4 bids 2NT. The 2011 writeup has 2NT as game-forcing with 14–15, but Wbridge5 bids 2NT with a minimum.

Opener jumped to 3♠ on only 2 boards, each with 4 spades and 16–17 points.

Reopening double

Responder may pass with length in LHO’s suit, but opener seldom reopens with a double. It takes extra values and support for both unbid suits. The probe gave opener 0–2 clubs.

Of the 71 hands with 5 hearts and 3+ cards in both spades and diamonds, 48 passed, mostly with 11–14 HCP, and 8 doubled. For example, ♠AQ108 ♥K10862 ♦KQ63 ♣- doubles, but ♠J53 ♥AJ532 ♦K94 ♣K10 passes. The 2♠, 2NT and 3♦ rows come from 3–4 boards each.

If LHO’s overcall is raised, opener doubles for takeout with shortness.

Opener doubled 16 of the 44 hands with 5 hearts and 0–1 spades, for example ♠- ♥KQ1076 ♦A1095 ♣A1087. Another 16 of them passed with 11–14 HCP.

Cuebid

Over responder’s cuebid, opener’s rebids are natural. 3♥ is the default.

Unusual 2NT

Over a 1NT overcall, responder’s 2NT shows both minors. Opener picks one.

The pass and 4NT rows come from 10 boards each. Every 4NT hand had 0–3 spades and length in both minors.

Maximal double

When the opponents bid up to just below 3 of the opened major, opener’s double invites game.

For example, ♠KQJ83 ♥A ♦Q972 ♣A104 doubles. The 2011 writeup has the maximal double at 16–17 and 4♠ at 18+. Wbridge5 doubles with 18–20 and also bids 4♠ with shapely hands from 16 points.

The same double works over 1♥ (2♦) 2♥ (3♦).

For example, ♠A ♥AKQ87 ♦632 ♣K986 doubles. Opener bid 4♦ on 2 boards, each with 6+ hearts and 0–1 diamond.

Not probed

• Responder’s calls with 4+ cards in opener’s major over overcalls other than 1♥ (1♠), and with 11+ HCP.
• Responder’s double of other 2-level overcalls (2♦, 1♥ (2♠)) and of a 2NT overcall.
• Responder’s second call after a negative double, and opener’s rebids after the 3-level takeout double of 1♠ (3♥).
• Support doubles over 2♦ or 2♥ after 1♥ - 1♠, and support redoubles at the 3-level.

Natural 1♣♦

The minor openings are the most frequent openings. Particularly, 1♣ is the most frequent, 1♦ the second. Therefore, it is important to learn the continuation of these openings.

The minor openings can be made from three kinds of hands:

• Open the longer minor in a balanced hand with 12–14 or 18–19 HCP without a 5-card major.
• Open the longest suit in an unbalanced hand with normal openings strength.
• Open the longest suit in a 3-suiter or 5-4-3-1 with 2♣ strength where the 5-card suit is a minor. See also the dedicated section.

Opener probably has a 4-card major. Therefore, responder bids a major first whenever it can. A notrump or a support in minor always denies a biddable major.

Responses to 1♣

The 1NT response is always constructive because there is no suit below clubs. When 1NT acts as a dustbin, responder bids 1NT to show a suit below the opening. This is obviously not the case for 1♣.

Choice of new suit

1. Choose the longest suit.
2. To break a tie, bid the cheapest call for 4-4, the highest suit for 5-5 or above.
3. Nevertheless, if responder cannot virtually 2/1 (< 12 points) but has normal responding strength (5+ HCP) and a biddable major, skip diamonds unless 6+ cards or at least AJxxx or KQJxx.

The partnership can usually make 2 of a suit and sometimes 1NT with normal responding strength. Bypassing diamonds slightly preempts in a partscore dog fight. However, when responding with void clubs and insufficient strength, responder bids 1♦ to seek 1♠/♥.

• ♠K965 ♥65 ♦KJ863 ♣98: Bid 1♠. Skip diamonds because you cannot force to game.
• ♠10983 ♥9 ♦KQJ103 ♣J72: Bid 1♦. These diamonds are eligible.
• ♠KQ93 ♥72 ♦AK73 ♣J63: Bid 1♦ because you can force to game.
• ♠KQ105 ♥7643 ♦J642 ♣10: Bid 1♥. Skip diamonds, and then 1♥ is the cheaper call.
• ♠Q974 ♥A1062 ♦AQ108 ♣7: Bid 1♦. No skipping for a game-forcing hand.

Simple raise

The 2♣ simple raise is not so simple.

For preemption, responder raises to 2♣ with 4+ clubs and no 4-card major in a non-constructive hand. This is the only case where 2♣ shows only 4 clubs.

For a constructive hand, responder jumps to 3♣ with 5+ clubs, but a balanced 7–9 HCP hand prefers constructive 1NT. Probing Wbridge5 5.12 shows no limit raise in clubs: stronger hands bid 1♦, 2NT, 3NT, or a splinter.

• ♠976 ♥965 ♦A109 ♣J1085: Bid 2♣. This hand is too weak for constructive 1NT.
• ♠QJ6 ♥J5 ♦J932 ♣J987: Bid 1♦. This hand is too weak for constructive 1NT.
• ♠964 ♥104 ♦AJ65 ♣A1094: Bid 1NT. The constructive 1NT is preferred over a minor suit.
• ♠53 ♥K84 ♦432 ♣KQ765: Bid 1NT. The constructive 1NT is preferred over a minor suit.
• ♠A75 ♥7 ♦874 ♣QJ6532: Bid 3♣. Make a constructive raise with unbalanced distribution.

Adjusted responses by a passed responder

Since responder has made a limit pass, which denies strength of opening, new-suit responses are no longer forcing.

Jump shifts from 2♥ on are fit-showing because responder gave up preemptive opening.

Responses to 1♦

Choice of new suit

1. Choose the longest suit.
2. To break a tie, bid the cheapest call for 4-4, the highest suit for 5-5 or above.

Adjusted responses by a passed responder

Not probed

• P - 1♣ - 2♦ and 2♥, and P - 1♦ - 3♣: no board.
• Responses above 21 HCP, except 3=3=3=4 hands with 22 HCP.

1♦ response

The 1♦ response usually shows 4+ cards and 6+ points. Such 1♣ - 1♦ is the most constructive auction. Because it is too constructive and shows no major, modern bridge players make many reasonable adjustments to the 1♦ response.

Wbridge5 is no exception. It adjusts 1♦ according to responder’s strength.

• 6–11 points: With a biddable major, skip diamonds unless 6+ cards or at least AJxxx or KQJxx.
• 17+ points: Bid strategic 1♦ with some hands indescribable by strong jump shifts.

Opener’s rebids

In Wbridge5, a 1NT rebid always denies biddable major because 1NT is difficult to make with average strength. Moreover, no singleton is allowed in the 1NT rebid. Therefore, responder can buy 2♠/♥ with only 5 cards.

In contrast, the 2NT rebid shows a balanced hand or 2=2=4=5. A 4-card major is allowed in a balanced hand. So descriptive can 2NT be because there is almost always 23+ HCP in the partnership. Since 2NT collects all balanced hands, the strong jump shifts 2♠/♥ contain 5+ clubs unless 2♥ with 4-4-4-1.

Beware that all these rebids are nonforcing. Responder can always pass when a game is unlikely.

The rebidding strategy is the same for all suit responses. The strategy is described in the page of major rebids for frequency and a more general overview.

A hand with 20 HCP and 6-3-2-2 is strong enough to open 2♣. Therefore, the 3NT still shows 18–19 HCP.

The 2♦ rebid is surprisingly unlimited. This unusual treatment produces good results in practice. Tactics are described in a dedicated subsection [not yet written].

Not probed

• The P row: no probe dealt 1♣ - 1♦ with opener in 3rd or 4th seat.

1♥♠ responses

The 1♠ and 1♥ responses always show 4+ cards, usually 6–16 points. If the opened suit is void, these responses can be made with insufficient strength.

These responses are a major tool to find a major fit in a 5-card major system. They take care of situations where opener has no more cards than responder in a major. Although opener might still have a 5-card major which is blocked by a longer minor, these patterns are rare and hence temporarily neglected by responder.

Opener’s rebids

The 2NT rebid is highly descriptive, so opener shall always consider this rebid first even if a major fit is found.

Thereafter, opener shall be eager to show a major fit. Failure to show a major fit denies 4-card support.

Found major fit

These rebids show 4+ cards in the responded major. The partner will not play in another suit (but a notrump game is still possible).

Major fit not found

By not bidding 2NT nor showing a major fit, opener denies a major fit. Opener has at most 3 cards in the responded major.

• Minimum: Never bid over 2 of own suit.
• Medium: Simply bid a new suit.
• Maximum: Bid over 2 of own suit.

Opened 1♣

Opener always raises with 4-card support even at the last 2 seats to silence balancing overcalls.

Opened 1♦

Summary of rebidding strategy

This strategy also applies to 1♣ - 1♦, but there are different considerations between over 1♦ and over a major rebid, so they deserve different pages.

Minimum

There are strict requirements for 1NT to make it balanced and specific, enabling more evasion from 1NT with weak hands.

1. Try to bid a major.
2. Bid 1NT if balanced or 5-4-2-2.
3. Bid a minor.

The tradeoff is that opener sometimes rebids a minor with short opened minor, but this situation shall not cause problems because bidding structure is unaffected.

Rebidding the opened suit usually shows 6+ cards, but only 5 cards with 5-4-3-1 or 5-4-4-0 where the 4-card suits is blocked. Responder may still pass to play the 5-2 fit.

The 1♦ - 1♠ - 2♣ auction occasionally contains only 4 diamonds due to 1=4=4=4. Responder still chooses diamonds with equal preference because opener’s diamonds are no shorter than clubs.

Medium

Bid a suit at the cheapest level. Opener must have an unbalanced hand and thus an eligible suit to bid, or 1NT would have been opened.

Maximum

1. Bid 2NT if balanced.
2. Show a major fit if present.
3. Bid 3NT with 6-3-3-2 but avoid missing a 3-5 major fit.
4. Bid a minor.

Not probed

• Rebids in 3rd and 4th seat other than 1♣ - 1♥ with 3 hearts in 3rd seat: the other P rows, and the raise with 4-card support at the last 2 seats.
• The 4M row other than after 1♣ - 1♥.
• The 4m row after a 1♥ response and the double-jump splinter after a 1♠ response: no board (1 board each after the other major).
• 1♦ - 1♥ - 3NT: no board.

Second responses

This page covers responder’s second call after opener’s 1NT rebid or a new suit at the 1-level. Opener’s rebids are on the pages of the 1♦ response and the 1♥♠ responses.

After a 1NT rebid

Opener’s 1NT shows 12–14 HCP, balanced or 5-4-2-2, and 2–3 cards in a major responded. Responder can sign off in 2 of a 5-card major with a weak hand. Stronger hands with 5+ cards in the responded suit start with Roudy 2♣.

Responded a major

After 1♦ - 1M - 1NT, a 2♦ preference shows 6–10 HCP and 3+ diamonds. After 1♠, 5-5 majors with 11–13 HCP jump to 3♥.

• ♠96542 ♥KQJ2 ♦10 ♣J42: Bid 2♥ over 1♣ - 1♠ - 1NT.
• ♠K8653 ♥AKJ2 ♦10 ♣874: Bid 2♣ over 1♣ - 1♠ - 1NT. This is Roudy.

Probing Wbridge5 5.12 shows 2♣ in 1♣ - 1♠ - 1NT also from 4♠ and 4♣ with 8–10 HCP. What responder does after opener’s answer was not probed.

Responded 1♦

• ♠1062 ♥Q ♦KJ6543 ♣A52: Bid 2♦.
• ♠9 ♥A62 ♦A98432 ♣K42: Bid 3♦.

Answering Roudy

Opener answers in the short-long-long-short coding of Roudy. The answer is about responder’s suit, so 2♥ shows 3-card support for spades in 1♣ - 1♠ - 1NT - 2♣. A maximum with 3-card support and 5 clubs bids 3♣, so 2♠ has only 4 clubs after a 1♣ opening.

• ♠1032 ♥J10 ♦AK6 ♣AJ983: Bid 2♦ over 1♣ - 1♥ - 1NT - 2♣.
• ♠63 ♥AK2 ♦954 ♣KQ543: Bid 2♥ over 1♣ - 1♥ - 1NT - 2♣.
• ♠K84 ♥Q104 ♦KQ9 ♣A842: Bid 2♠ over 1♣ - 1♥ - 1NT - 2♣.
• ♠K82 ♥A2 ♦KJ9 ♣K10983: Bid 2NT over 1♣ - 1♥ - 1NT - 2♣.
• ♠82 ♥Q96 ♦K97 ♣AKQ94: Bid 3♣ over 1♣ - 1♥ - 1NT - 2♣.

The help file also lists 3♦ for a maximum with 3-card support and 5 diamonds. The probes held no such hand.

Fourth suit

A fourth suit is forcing only when it is 2♣ or 2♦. Others are natural. In particular, 1♠ in 1♣ - 1♦ - 1♥ - 1♠ shows 4 spades.

After 1m - 1♥ - 1♠

After 1♦ - 1♥ - 1♠, 2♣ is the fourth suit. A 2♦ preference shows 6–10 HCP and 3+ diamonds, and 3♦ invites with 4+ diamonds.

• ♠J53 ♥AJ532 ♦K94 ♣K10: Bid 2♦ over 1♣ - 1♥ - 1♠.

After 1♣ - 1♦ - 1♥

• ♠KQ64 ♥974 ♦AQ75 ♣85: Bid 1♠.
• ♠KQ54 ♥K2 ♦KQ876 ♣107: Bid 2♠.

Not probed

• 1♦ - 1♠ - 1NT: the table after a major rests on 1♣ - 1♥, 1♣ - 1♠ and 1♦ - 1♥.
• Opener’s answer to Roudy after a 1♦ opening, the 3♦ answer, and responder’s call after any answer.
• Fourth suits other than the three tabled, e.g. 2♥ in 1♣ - 1♦ - 1♠.

Slam bidding

In this section, responder is assumed to have strength sufficient for a strong jump shift. However, a SJS is not always the best move. The 1♣ - 1♦ and 1♦ - 2♣ responses and Splinter come to help when SJS ill describes the hand.

Slams are games after all, so the seeking process is definitely major > notrump > minor. Always bid a SJS when a 4-card major is present although the SJS itself can be a minor.

Strong jump shifts

SJS is a frequent slam bidding utility. SJS in Wbridge5 shows 17+ points and 4+ cards. There are few other requirements, even fewer than Soloway jump shifts. This practically confines 1-over-1 responses to 6–16 points, except that 1♦ catches strong hands unsuitable for SJS.

Opener’s rebids over major SJS

SJS is forcing and opener rebids below the major game. Most of the time, responder has 17–19 points, so opener shall be eager to describe distribution instead of strength. Opener is the captain unless a notrump is bid. Notrump shows strength as well as balancedness because there are 2NT and 3NT to choose from.

Special auctions after 1♣

Slam bidding becomes tricky when there is no side suit to jump. Moreover, 4-card support is not a fit. Therefore, there must be some continuations to show notrump to handle 3=3=3=4 at least. Notrump continuations exist anyway then, they take precedence over a pure 2♦ for 3-2=4=4 because notrump games are considered before minor games.

Precedence of bids

RKCB is unlisted because only unusual hands deserve that 4NT. RKCB in later rounds is better most of the time.

1. Any SJS with a 4-card major
2. Quantitative invitation
3. SJS 2♦
4. Splinter
5. Catchall 1♦

It is too risky to delay Splinter after 1♦ because opener is likely to bid a major.

SJS 2♦

Because minor games are cheaper and at least 5-level, be wary of them and manage to find a major game. The 3♥ and 3♠ rebids are reserved for 5-card majors skipped in opening due to a longer minor, which is clubs here. Other rebids have the same meanings as rebids to major SJS, but a major rebid is considered first.

Opener still rebids below 4♦ because it wastes too much space to bid a Splinter from 4♥ on. The 3♦ rebid catches unbalanced diamond fits with no biddable major.

Quantitative invitation to 6NT

With 17–18 HCP and 2–3♠ 2–3♥ 2–4♦ 4+♣, invite to 6NT quantitatively. Fake a catchall 1♦ first because direct 4NT is reserved for RKCB. Probing Wbridge5 5.12 shows a direct 4NT instead with 16–17 HCP and 5+ clubs. If the auction is interfered, cuebid or redouble to show a generic slam try. The following show reactions to opener’s rebids in a constructive auction.

• Opener rebids 1♥ or 1♠: Bid 4NT. Opener shall recognize this special auction as quantitative invitation.
• Opener rebids 1NT: Ask strength with Roudy.
• Opener rebids 2♣ or 2♦: Opener has distribution, better to seek a minor slam instead.
• Opener rebids 2♥ or above: Seek a grand slam, e.g. bid 5NT to invite to both 7NT and 7♣.

Quantitative invitation to 7NT

Direct 5NT is quantitative invitation to 7NT. Bidding a grand slam requires about 2/3 probability, so stricter rules apply. Quantitatively invite to 7NT with 20–22 HCP and 3=3=3=4. Bid a SJS for any side suit. Bid 1♦ or 4NT for a club fit. Probing Wbridge5 5.12 found 5NT on all 300 hands with 20–22 HCP and 3=3=3=4.

Opener signs off because responder has precisely described the hand.

Special auctions after 1♦

There are fewer exceptions than 1♣. There is no need for a notrump strain because responder can raise with mere 4 diamonds. The 1♦ - 2♣ - * - 3♦ is a natural SJS in diamonds, the assumed meaning of a delayed raise after 2/1.

The only possible responses of a responder with 17+ points are as follows.

Precedence of bids

1. Bid 3♣ if clubs is longer than each major
2. Choose among 2♠, 2♥, 2♣ as if they were 1♠, 1♥, 2♣ respectively.
3. Bid 2♣ since only diamonds is biddable.

Not probed

• The 3♥ and 3♠ rebids after 1♣ - 2♦: only 1 board held a 5-card major.
• The 3♣ strong jump shift over 1♦ (18+, 6+♣): no board.
• Responders above 21 HCP, except 3=3=3=4 hands with 22 HCP.
• Responder’s second call with 17+ HCP after 1♣ - 1♦ - 1♠, 1NT, 2♣ or higher, opener’s answer to 4NT after 1♣ - 1♦ - 1♥ or 1♠, and opener’s call after a direct 5NT.
• Responder’s second call after 1♦ - 2♣, including the delayed raise 1♦ - 2♣ - * - 3♦: no auction past 1♦ - 2♣ was probed.
• Slam tries after interference.

Competitive bidding

Responses after a takeout double

The takeout double shows opening values, so responder bids more preemptively. There are some adjustments to the basic structure.

Playing 2NT is infeasible now as 1♣xx is more profitable. As a result, the meaning of 2NT is changed to a convention. For its original meaning, redouble instead. Probing Wbridge5 5.12 shows that 3NT over 1♣ (X) is still natural.

Jump shifts become weak if responder unpassed. Redouble to show strength for original strong jump shifts. Keep in mind that fit-showing by a passed responder are unadjusted because the previous pass denies both jump shifts.

Responses to 1♣ (Dbl)

A simple raise can now be made with only 5 points. The jump shifts are weak for an unpassed responder.

Probing Wbridge5 5.12 shows no weak 2♦. A weak hand with 6+ diamonds bids 1♦.

A passed responder keeps the fit-showing jumps unchanged.

Responses to 1♦ (Dbl)

A simple raise can now be made with only 5 points. The jump shifts are weak for an unpassed responder.

A passed responder keeps the fit-showing jumps unchanged.

Responses after a simple suit overcall

Wbridge5 employs French convention for such low-level competitive auctions. The French insist on showing length of hearts quickly to compete with latent adverse spades.

Collante

The French word collante means “sticky” in English. This means that a negative double after a 1♦ or 1♥ overcall shows exactly 4 cards in the next suit viz ♥ or ♠ respectively. As a consequence, the direct bid of the suit now shows 5+ cards.

Be aware that Collante only affects one suit. The meaning of 1♠ in 1♣ (1♦) 1♠ is the same as 1♣ - 1♠, which shows 4+ cards in spades, because only hearts is affected by (1♦).

Rodrigue

This convention is uncommon in France, but is used by Wbridge5. After a 1♠ overcall, Wbridge5 gives up the simple raise for a negative free bid of hearts. This bid differentiates with the negative double by showing 5+ cards of hearts, making the negative double show exactly 4 cards.

Wbridge5 madly insists on showing length of hearts quickly to compete with latent adverse spades.

Higher overcalls

Over 1♦ (2♣), responder shows hearts first, as in Rodrigue. A 2♦ bid shows 4+ hearts, and the double shows both majors. A hand with 4 spades but not 4 hearts does not double.

All 59 hands that bid 2♦ held 4–5 hearts. With 5 hearts, responder bids 2♦ with 6–10 HCP and 2♥ with more. For example, ♠AQ97 ♥A763 ♦1093 ♣94 doubles, and ♠73 ♥AJ75 ♦J1062 ♣AJ6 bids 2♦.

Over a weak jump overcall, Collante carries on to the 2-level: the double of 2♥ shows spades. At the 3-level the double shows 4 spades and 10+ HCP.

With 5 spades, responder doubles with 7–9 HCP and bids 2♠ with more.

For example, ♠AKQ10 ♥972 ♦Q2 ♣K1087 doubles 1♣ (3♥). The probes for this section gave responder 0–4 cards in opener’s minor.

Over Precise Michaels

Over 1♣, the opponents’ 2♦ is a Precise Michaels bid for both majors, because the opponents play Wbridge5’s own defaults. Responder never doubles it. Its calls are tabled with the other opponents’ two-suiters.

Opener’s rebids after a negative double

Responder’s calls mean the same with or without LHO’s overcall, so opener rebids as in an uncontested auction. The negative double stands for a response in the major it shows. Since the double shows exactly 4 cards, opener raises only with 4-card support.

Over 1♣ (1♦) Dbl

Opener raises as over 1♣ - 1♥, but the cheap 1♥ is now available for a minimum raise. Each raise therefore shows a little more.

With 4 hearts and a singleton, a strong opener can also make a double jump in the short suit to show a splinter (3♠, 4♦) or jump to 4♣ with 6 clubs.

• ♠94 ♥Q732 ♦KQ ♣AJ1094: Bid 1♥ over 1♣ (1♦) X. This is a minimum raise.
• ♠K10 ♥Q962 ♦93 ♣AKQ97: Bid 2♥ over 1♣ (1♦) X.
• ♠A8 ♥KJ83 ♦4 ♣KQJ654: Bid 3♥ over 1♣ (1♦) X.