Defensive bidding system

Welcome to Chen-Pang He (jdh8)'s defensive bidding system! This bidding system is based on Good, Better, Best by Jan Eric Larsson and my improvisation.

Hand evaluation

• High card points (HCP) : the well-known Milton Work's 4321 count
• Total points : HCP + distribution points (void = 3, singleton = 2, doubleton = 1, subtract 1 for each short suit with HCP)
• Zar points (ZP) : 6-4-2-1 + Zar distribution points (a + b + a - d, where the letters are the number of cards from the longest to the shortest suit)
• Fifths : 4.0–2.8–1.8–1.0–0.4, adjusted HCP for notrump contracts especially 3NT
• BUM-RAP : 4.5–3–1.5–0.75–0.25, adjusted HCP for suit contracts
• NLTC : Count 1.5–1.0–0.5 losers for each missing AKQ

NLTC is a good single hand evaluator but not very additive. It suits preemptive initial actions but not for showing supports. I have a blog article on that topic.

https://jdh8.org/nltc-a-good-single-hand-evaluator/

Stopper

We evaluate stopper quality as GIB does.

• Partial stop : length + HCP = 4
• Likely stop : length + HCP = 5
• Stop : A, QJx, or length + HCP at least 7
• Two stops : length + HCP at least 8

References

• Thomas Andrews. [Thomas's Bridge Fantasia](https://bridge.thomasoandrews.com/valuations/)
• Bridge Base. [GIB Bid Descriptions](https://www.bridgebase.com/doc/gib_descriptions.php)

Over natural (1X)

Due to insufficient strength, 1NT by passed hand becomes unusual.

Balancing overcall

Different from a direct overcall, a simple balancing overcall is tentative, while a jump overcall is sound.

Notrump overcalls

By unpassed hand, notrump overcalls are natural because we want a sound 2NT.

• 13–15 HCP: 1NT
• 16–18 HCP: X, then notrump
• 19–21 HCP: 2NT

Like a direct overcall, 1NT by passed hand is unusual.

Advances to (1X)-1Y

High strains

Raises are natural and non-forcing. Note that the overcall occasionally contains only 4 cards. We always raise to the 3-level with 4+ trumps.

Z, a suit higher than Y, is always a major suit. Bidding 1Z is forcing for constructiveness. Jump advances in Z are preemptive.

Notrump advances are natural in the sense of showing length or a stopper in the adverse suit.

As 1Z is pretty similar to a direct overcall, aggressor somehow mirrors the auction but without Rubens advances. Aggressor does not have a weak hand with 6+# because they would have jumped in the first place.

Low strains

Let's reword the auction as (1Y)-1Z to discuss X, a suit lower than Y. X is always a minor suit. We are more interested in 3NT than a minor suit game. Therefore, we bear the presence of a stopper in mind. Sometimes we have to bid a 4-card 2X because we lack a stopper to bid notrump.

Aggressor still has the chance to query a stopper with a cuebid. That is why we can bid fairly naturally here.

Rebidding to a lower strain is similar to 2/1 or Drury. Returning to the own suit is the weakest action. If advancer has passed, it is also good to pass with a balanced minimum.

Middle strains

The other suits are Rubens advances. Cuebids and suits in between are transfers. After rephrasing the auction as (1X)-1Z, Y is a suit in between. There is no distinction between X and Y. Transfer supports are special nevertheless.

• 4steps = 2Z − 1 : limit raise or better, 3+ support
• 9steps = 3Z − 1 : mixed raise, 4+ support
• Other 2XY : 9+ HCP, usually 5+ cards
• Other 3XY : Game try with 6+ cards

Despite that we have skipped the cuebid, aggressor can dissuade further investigation by simply accepting the transfer.

Advances to (1X)-X

Transfer advances are active from 3Q on. This way, we can separate paths to suit games by strength and by length.

Advances to (1X)-1NT

We play Gladiator at (1M)-1NT, which is more effective against a major suit opening, especially 1 ♠ . Aggressor can have 5 hearts at (1 ♠ )-1NT because 2 ♥ would be an underbid. We get an additional cuebid to invite with 3 hearts, roughly equivalent to Puppet Stayman. There is also an indirect 3NT for choice of games with 3 hearts.

This version of Gladiator originates from a BTU gadget:

https://www.ptt.cc/man/BridgeClub/D6D1/D49B/M.983965409.A.html

Our agreement that slow 3NT has 3= hearts persists if RHO bids up to 2NT.

I have not yet come up with how we utilize the slow cuebid.

Otherwise, we simply ignore the opening. Take the 1NT overcall as an opening.

Over strong notrump

Good, Better, Best recommends using conventional double over a strong notrump. We play Woolsey in all seats. We consider a natural notrump opening strong if at least half of the hands contain 15+ HCP. For instance, 14–16 is considered strong but 13–15 is not.

Over weak notrump

We play Landy against a weak notrump. We consider a natural notrump opening weak if more than half of the hands contain 14 or fewer HCP. This simple defense undermines their systems on approach over (1NT)-2 ♣ . Meanwhile, we still threat to stop in our natural 2 ♦ .

By passed hand, we play the defense against a strong notrump.

Over natural (2X)

Reverse Lebensohl

Though usually treated the same, there is a significant difference between (2X)-Dbl and 1NT-(2X): we cannot pass boring hands in the former situation! After a long discussion, we came to a conclusion that reverse Lebensohl with Rubens advances is a better alternative than transfer or standard counterparts.

As opposed to the standard/original Lebensohl, this 2NT relay handles constructive hands (8+ HCP or 7+ HCP by passed hand) while directly bidding a suit below 3X is weak. Since an in-shape takeout is short in the adverse suit, advancer is more likely to have a stopper. Inviting with 2NT right-sides the contract more often than not.

I put special cases before general rules to generate correct BSS files.