Natural (1y)

A 1-of-a-suit opening usually shows at least average strength and length in the suit. Defense against conventional openings is covered in later chapters, as far as Wbridge5 itself plays them.

Opponents’ auction deprives little bidding space and shows strength. Therefore, Wbridge5 is more preemptive here than in its constructive auctions.

Systems outside the book

The defensive chapters cover the systems Wbridge5 itself plays: its own, SEF and SAYC. A strong 1♣, Multi 2♦, Flannery 2♦, Precision 2♦ and Roman 2♦ belong to none of them and are out of scope.

Wbridge5 has no setting for these openings and gets no alerts, so it reads them by its own system. Probing Wbridge5 5.12 shows that it defends (1♣)-P-(1♦) as two natural bids, cuebidding 2♣ with 5-5 in the majors (246 of 300 hands) and overcalling a natural 2♦ with 6+♦ (162 of 300). It takes any (2♦) for a strong, game-forcing 2♦: with 8–18 HCP it passes 201 of 300 hands and never makes a takeout double, and a long diamond suit bids a natural 3♦, as with ♠J2 ♥54 ♦AK109854 ♣Q10.

Simple overcalls

Simple overcalls are constructive but somewhat limited. They show 5+ cards in the bid suit. Their strength depends on their level.

Hands with 16+ HCP are too strong for simple overcalls. They double first and then bid the suit in the next round. Probing Wbridge5 5.12 over (1♣) and (1♠) confirms the line. Of the hands with 5+ cards in an unbid suit that doubled or made a simple overcall, 18 of 96 still overcalled with 16 HCP, and 1 of 161 with 17+ HCP.

Probing Wbridge5 5.12 shows that simple overcalls hardly depend on vulnerability. Over (1♥) with 6+ HCP, 6 of 300 calls changed at unfavorable vulnerability and 4 at favorable, all of them jump overcalls, two-suiters or marginal 2♣ overcalls. Doubles and 1NT overcalls did not change. Nor did the minimum double: over (1♥) with 9–14 HCP, 0–2♥ and 3–4♠, all 88 doubles stood at unfavorable and at both vulnerable. The 7 changes were overcalls with 10 HCP that passed or bid lower, mostly 3♦ with 6 diamonds.

In Wbridge5, (1♣) 2♣ is natural instead of a Michaels cuebid. However, clubs was indeed an adverse suit, so a stronger hand is required to make such a turning bid. This natural cuebid is alertable.

Advances of simple overcalls are in Advancing overcalls.

Precise Michaels

Precise Michaels aka Michaëls précisés are Michaels cuebids which show both suits. These bids are shortcuts to show 5+ cards in 2 suits.

Precise Michaels are unlimited. Advancer is unlikely to pass out because the strain is never a held suit. Precise Michaels take precedence over takeout doubles because they are precise in distribution.

To avoid bidding an actual suit, Wbridge5 allocates bidding space as follows.

• Highest 2 nonadverse suits: Transfer, the bid below the lower suit.
• Top & bottom nonadverse suits: Cuebid or jump cuebid.
• Lowest 2 nonadverse suits: Unusual notrump.

Unusual notrump

Unusual notrump shows the lowest 2 nonadverse suits. The following notrump overcalls are unusual.

There is no need to express a natural 2NT. Takeout double takes care of such strong hands. In the direct seat, a passed hand cannot hold a strong notrump, so its 1NT is also unusual. Probing Wbridge5 5.12 shows that a passed hand’s 1NT in the balancing seat is natural, 10–11 HCP; see Natural 1NT overcall.

Opponents opened a minor

The 2♦ shows the highest 2 nonadverse suits, the unusual notrump the lowest 2, and the jump cuebid the top & bottom. Being unexpected, (1♣) 2♦ requires an alert outside of France, but (1♦) 2♦ is not alertable because this is the expected meaning of a cuebid.

Opponents opened a major

The cuebid shows the top & bottom nonadverse suits, the unusual notrump the lowest 2, and 3♣ the highest 2. The jump cuebid is a cuebid with 20+ points. Probing Wbridge5 5.12 confirms the range in points, though not in HCP. The points here add a length point for each card past the fifth. Over (1♥) with 5+♠, 5+♣ and 11+ HCP, 3♥ came up on 30 of 300 boards with 12–20 HCP but 19–23 points, e.g. ♠K9874 ♥6 ♦– ♣AKQ10962 (12 HCP, 19 points). The 2♥ cuebid went up to 21 points, so the two overlap at 19–21, and 3♥ is the commoner call from 20 points. Six hands with 23+ points doubled instead. Over (1♠) with 5+♥, 5+♣ and 18+ HCP, 3♠ came up on 282 of 300 boards, with 21–28 points. Of the other 18, 17 bid 2♠, all with 18 HCP and 21 points, and one doubled.

Probing Wbridge5 5.12 shows that 4NT depends on shape rather than strength. A 6-6 hand bids 4NT, but a 6-5 hand bids 2NT at any strength.

Strength

Most bids above lack description of strength because their strength depends on seat and vulnerability.

• Unfavorable: 13+, but 11+ if passed
• Both vulnerable: 12+, but 11+ if passed
• None vulnerable: 11+
• Favorable: 10+

Probing Wbridge5 5.12 confirms the steps. Over (1♥) with 5 diamonds, 5+ clubs and 4–13 HCP, Wbridge5 bid 2NT from 8 HCP at none vulnerable (9 more with 6–7 HCP), from 10 HCP at unfavorable (14 more with 6–9 HCP), and from 7 HCP at favorable (11 more with 5–6 HCP). For example, ♠9 ♥82 ♦A10764 ♣A10752 bids 2NT at none vulnerable but passes at unfavorable. Both vulnerable lies in between: 2NT on 188 of the 300 hands, against 219 at none and 155 at unfavorable. That example hand still bids 2NT.

Advances and the overcaller’s rebids are in Two-suited overcalls.

Natural 1NT overcall

A direct 1NT overcall shows 15–18 HCP, 1NT opening distribution, and a stopper in the adverse suit. Advancer plays systems on as over a 1NT opening. The balancing 1NTs, the changes made for the adverse suit, and the overcaller’s rebids are in their own chapter.

Takeout double

The takeout double is one of the earliest conventions in bridge. It shows one of the two kinds of hands.

• 12+ points with tolerance in all nonadverse suits
• 16+ HCP, unsuitable for a notrump or a Michaels

Because this call usually implies shortness in the adverse suit, advancer only passes with length in the adverse suit, converting the double into penalty. Otherwise, advancer is forced to bid a suit as cheap as possible with a weak hand. Opener with minimum hand can safely pass to complete the competition because of tolerance to each nonadverse suit.

Since a notrump and Michaels are far more specific, they take precedence over a takeout double. However, a takeout double takes precedence over a simple overcall because overcall can bid the suit after the double, which makes a more specific auction.

Probing Wbridge5 5.12 over (1♣) and (1♠), mostly with 16–22 HCP, shows the strong kind. Unbalanced hands that do not fit the minimum shape doubled on 20 of 74 boards with 15 HCP, 45 of 101 with 16, 55 of 65 with 17 and 37 of 45 with 18. Most of the others bid 1NT, overcalled or passed. Balanced hands with 16–18 HCP mostly bid 1NT, and from 19 HCP they all doubled. With 5+ cards in opener’s suit, Wbridge5 sometimes passes instead: 6 of 58 such hands over (1♣) and 7 of 58 over (1♠), all with 16–17 HCP, e.g. ♠K732 ♥J85 ♦A ♣AKJ53 over (1♣).

Shape of a minimum takeout double

The hand must be in shape to double with < 16 HCP. Distribution points from the adverse suit is reconsidered as -1, 1, 3, 5 to upgrade 3-suiters and to downgrade flat hands.

• 0–3 cards in the adverse suit
• 3–5 cards in each nonadverse major
• 2–5 cards in each nonadverse minor

Probing Wbridge5 5.12 over (1♣) and (1♠), with hands short in opener’s suit, confirms the three limits. Below 15 HCP every double held 3+ cards in each unbid major and 2+ in each unbid minor, apart from one 1-7-5-0 hand with 13 HCP over both and one 1-4-2-6 hand with 13 HCP over (1♠). Over (1♠) with a doubleton heart, Wbridge5 doubled only with 15–16 HCP (18 of 300 boards). Below that it bid a minor, bid 2NT or passed, e.g. ♠K2 ♥62 ♦K832 ♣AKJ93 bids 2♣ with 14 HCP.

The recount fits the floor. Counting opener’s suit as -1, 1, 3, 5 points for 3, 2, 1, 0 cards and the other suits as usual, hands in that shape with under 15 HCP and no 5-card suit doubled (1♣) from 11 points, on 47 of 51 boards with 12 points and on all but one from 13. Over (1♠) the floor is a point higher: 2 of 20 hands doubled with 11 points, 4 of 19 with 12, 12 of 14 with 13 and 34 of 35 from 14. In HCP the floor falls as opener’s suit shortens. Over (1♣) with 4-4 in the majors, Wbridge5 doubled from 11 HCP with 3 clubs, 10 with 2, 9 with 1 and 8 with a void (the probe’s floor; only 7 boards had a void), and always from 1 HCP more, until balanced hands with 15 HCP began to bid 1NT. For example, ♠KJ87 ♥K1074 ♦1054 ♣K4 doubles (1♣) with 10 HCP, but ♠J972 ♥KQJ9 ♦K7 ♣762 passes.

A 5-card major does not rule out the double. Over (1♦) Wbridge5 doubled ♠KJ83 ♥AQJ32 ♦– ♣Q972 rather than overcall 1♥. Over (1♣) with 5 hearts and 11–14 HCP, it doubled with 4 spades and 0–1 club (all 50 boards) and overcalled 1♥ with 3 spades or 2 clubs (all 179), except that 3-5-5-0 hands bid the unusual 2NT. With 15 HCP the two calls split evenly, and with 16 every hand doubled, bar one 3-5-5-0. For example, ♠QJ86 ♥KJ654 ♦A52 ♣7 doubles (1♣), while ♠9864 ♥AQJ109 ♦A5 ♣Q8 overcalls 1♥.

Advances and the doubler’s rebids are in Takeout doubles, and advancer’s doubles in Responsive doubles.

Weak jump overcalls

A jump in a new suit is always a weak jump overcall by default. This also applies to high-level jumps such as (1♣) 4♥.

Weak jump overcalls share the same criteria as preemptive openings. For example, (1♣) 2♥ shows the same length and strength as a 2♥ opening.

If partner has passed, Wbridge5 preempts as aggressively as with a 3rd-seat opening, for strength is concentrated in a known opponent.

Unlike a 1st-seat opening, the jump overcall depends on both sides’ vulnerability. Probing Wbridge5 5.12 over (1♣) with 6–7 hearts and 3–11 HCP, 300 boards per vulnerability, shows:

• Unfavorable: 2♥ needs about 6 HCP with 6 cards. Of the 6-card hands with 3–5 HCP, 31 of 38 passed, and most 6 HCP hands overcalled 1♥. A 7-card suit bids a level lower: 2♥ with 4–8 HCP, 3♥ with 7–11, 4♥ only with 10–11.
• None vulnerable: 6-card 2♥ from 3 HCP, but 20 of 38 hands with 3–5 HCP passed and many 6–9 HCP hands overcalled 1♥. With 7 cards, 3♥ with 4–9 HCP, 4♥ with 7–11.
• Favorable: 6-card 2♥ from 3 HCP, and only 3 of 38 hands with 3–5 HCP passed. Most 6–8 HCP hands that overcall 1♥ at none vulnerable jump to 2♥.
• Both vulnerable: in between. 6-card 2♥ needs 5 HCP, and 30 of the 38 hands with 3–5 HCP passed. A 7-card suit bids 2♥ with 4–8 HCP, 3♥ with 5–10, 4♥ with 9–11. Of the 300 calls, 35 differed from none vulnerable and 24 from unfavorable.

For example, ♠K83 ♥J109873 ♦K95 ♣6 overcalls (1♣) 1♥ at none vulnerable but 2♥ at favorable.

Advancer responds as to a weak opening; see Advancing overcalls.

Gambling 3NT overcall

A gambling 3NT over an opening requires a stopper in the adverse suit. This overcall still shows a 7+-card minor led by AKQ with no stopper in the other side suits.

Over a minor opening, 3NT is meant to hold the other minor, so advancer without enough stoppers to play 3NT corrects to the assumed minor. Probing Wbridge5 5.12 shows that it overcalls that minor instead, e.g. ♠72 ♥10 ♦AKQ8642 ♣KJ10 overcalls (1♣) 1♦.

The 4-level cuebids

The 4-level cuebids are blockbuster takeouts, showing 20+ points and 4+ cards in every nonadverse suit. What a cunning way to use 4-level cuebids!

Probing Wbridge5 5.12 found 4 of them among 600 hands with 16–22 HCP over (1♣) and (1♠), all with 21–24 points: 4♣ with 4-4-4-1 and 20 or 22 HCP, and 4♠ with ♠– ♥AQJ5 ♦A1064 ♣AK852 or ♠10 ♥AKJ7 ♦AQ74 ♣AK92. The other 3-suiters short in opener’s suit, with 15–18 HCP and 17–20 points, doubled.

Over a Bergen raise

By default the opponents play Bergen raises, so (1♥) P (3♣) is an artificial heart raise. Probing Wbridge5 5.12 in 4th seat with 8–20 HCP shows that it passes most hands, even strong ones. The double shows clubs.

Opponents playing SAYC have no Bergen, so their 3♣ is natural. The same 300 hands then drew 224 of the same calls. The double turns into takeout, and a cuebid of 3♥ appears.

For example, ♠94 ♥Q732 ♦KQ ♣AJ1094 doubles Bergen 3♣ but passes a natural 3♣. ♠AK ♥AK3 ♦K76 ♣Q10432 passes Bergen 3♣ but doubles a natural 3♣, and ♠AKQ64 ♥Q108 ♦AJ752 ♣— bids 3♠ over Bergen but 3♥ over a natural 3♣.

The 2NT raise does not matter in the same way. Over (1♥) P (2NT), the default special 2NT, SAYC’s Jacoby 2NT and SEF’s 2NT drew the same 300 calls on the same 300 hands.

Not probed

• A passed hand’s unusual 1NT over openings other than (1♥).
• 4NT over (1♠).
• Vulnerability for two-suiters and jump overcalls beyond (1♥) 2NT with the minors, hearts over (1♣), and random hands over (1♥) at favorable and unfavorable, and for a passed hand’s two-suiters.
• Jump overcalls after partner has passed, P (1y).
• The gambling 3NT over (1♦) and over a major, apart from one 3NT over (1♠) among random hands.
• The 4-level cuebids beyond 4 boards among strong hands.
• Bergen raises other than (1♥) P (3♣).
• Targeted probes of the minimum takeout double over (1♦) and (1♥), and over (1♠) with 3 spades (29 boards without a 5-card suit). Five spades and four hearts over a minor were not targeted either: over (1♣) with a singleton club and under 16 HCP they doubled on 22 of 43 boards.
• The jump cuebid of a major below 18 HCP over (1♠), and the (1♥) X with 23+ points (6 boards).