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.

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.

After (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

Recommended by Good, Better, Best, we play (Meckwell) DONT against a strong notrump. 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 the first seat (1NT), we use the original DONT except that the other suit in 2 is always a major. Responses are natural P/C. Responder can also convert the constructive double to penalty with INV+ hands.

We use Meckwell DONT in the other seats. Potential penalty is not that useful since at least one of us has a passed hand.

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)

Transfer Lebensohl

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

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