Defensive bidding system

Welcome to Chen-Pang He (jdh8)'s defensive bidding system! We use the distribution syntax and abbreviations provided by WBF.

http://www.worldbridge.org/wp-content/uploads/2017/04/Guidetocompletion.pdf

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

Notrump overcalls

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

Advances to (1X)-1Y

Raises and the higher new suit are more suit-oriented, so we use evaluations better for suit contracts. We use the jump cuebid as a mixed raise.

Notrump and the lower new suit are natural and non-forcing. Note that the lower new suit is always a minor suit. We are more interested in 3NT than a minor suit game. If you have a strong hand without a stopper, cuebid to ask for a stopper.

We use Rubens advances, where calls from the direct cuebid to the suit below the single raise are transfers.

• Transfer to a new suit : 9+ HCP, 5+ cards in the new suit
• Transfer support : INV+, 3+ card support, opening strength (or 10+ HCP by PH)

The direct cuebid also asks for a stopper for the strong hands.

Advances to (1X)-1NT

Over artificial forcing (1 ♣ )

Our defense was derived from Terrorist's Moscito. Note that we also use this defense even when opponents' 1 ♣ is not necessarily strong (e.g. Polish Club).

We pass strong hands since we are always given a chance to bid again. This is arguably the only sane usage of coming out after a pass.

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 Meckwell DONT as if against a strong notrump.

Over strong (2 ♣ )

We simply play Mathe with follow-ups same as Landy over (2 ♣ ). The strong 2 ♣ is already self-preemptive, so we don't need to worry about that.

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.

There are subtle differences among adverse suits. We adjust them case by case.

Note that this structure also works for artificial (2m) openings without further modification.