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.

The Wbridge5 program overestimates values of unbalanced hands. It bid 2/1 with highly unbalanced hands with 9~10 HCP but ended up with no playable game. I have devised a better strategy.

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

There are 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 okay for 1♥-2♦)

These criteria are based on visualization of maximum hands to pass the semiforcing 1NT, i.e. 13~14 HCP and usually 5-3=3=2. Nevertheless, under this circumstance, 1♥ opener's best distribution for responder to bid 2♦ is 4=5=3=1, 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

Simple new suit

13~18 points, 4+ cards.

2 of own suit

13~17 points, 6+ cards or fallback.

2NT

11~14 HCP, 5~6 cards in the opened suit, 2~3 cards in the responded suit, 2~4 cards in each of the other suits.

Reverse

17~21 points, 4+ cards.

Simple raise (3-level)

13~18 points, 4+ cards.

Jump to 3 of a new suit

19~21 points, 4+ cards.

3 of own suit

18~21 points, 6+ cards.

3NT

18~20 HCP, balanced.

Jump raise (4-level)

18~21 points, 4+ cards.

4 of a new suit

Splinter, 17~21 points, 0~1 card, 4+ support

4 of own suit

20~21 points, 7+ cards.

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.

3♥

17~21 points, 3+ cards.

4♣, 4♦

Splinter, 16~21 points, 0~1 card, 3+ hearts.

4♥

14~16 points, 3+ cards.

The 2NT rebid with a 6-card major

All of the following conditions shall be met to bid 2NT with a 6-card major.

• 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♥, bidding 2NT is okay due to the indirect 4♥ thereafter.

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 here and the 2nd overall. Note that 1♠-2♣; 2♠ is the only circumstance where a 6th card is for sure.

Raises

There is enough space to bid weak and strong hands under game for safety and bidding space respectively.

2M

Nonforcing, < 12 HCP, 2 cards

3m

Nonforcing, < 12 HCP, 4+ cards.

3M or 4m

Slam try, 16+ points, found a fit here.

4M or 5m

To play.

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.

Non-jump new suit

4+ cards, or 3 cards in 18+ HCP 5-3-3-2.

2NT

11~14 HCP, 2+ cards in every unbid suit.

Rebid 3 of own suit

12~15 points, 6+ cards.

Jump to 3 of a new suit

4+ cards, 18+ points.

3NT

Signoff, 15~17 HCP, 2+ cards in every unbid suit.

Rebid 4 of own suit

16+ points, 6+ cards.

4 of a new suit

Splinter, 17+ points, 0~1 card, found a fit in the last bid suit.

Opener rebid 2NT

The 2NT rebid shows balanced 12~14 HCP or 5-4-2-2 with 11~14 HCP where the 4-card suit is skipped. This rebid is the most frequent.

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

3NT

Signoff, 11~17 HCP.

The Wbridge5 program treats 4NT as the plain Blackwood, but I advocate that it shall be a quantitative invitation, which is more precise to find notrump slams.

There are futher 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.

3♣

12~17 points, 6+ cards.

4♣

18+ points, 6+ cards.

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.

3♣!

Roudy, 11+ HCP, 5+ diamonds.

3♦

Nonforcing, < 11 HCP, 6+ cards.

Over 1♠-2♦; 2NT

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

3♣!

Roudy, 5+ diamonds.

3♦

12~17 points, 6+ cards.

4♦

18+ points, 6+ cards.

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.

3♥

17+ points, 6+ cards.

4♥

12~16 points, 6+ cards.