2/1 game forcing

2/1 game forcing (Two-over-one game forcing) is a bidding system in modern contract bridge structured around the following responses to a one-level opening bid:

  1. a non-jump response in a new suit at the one-level is constructive and forcing for one round,
  2. a non-jump response in a new suit at the two-level is forcing to game, and
  3. a 1NT response is forcing for one round and indicates insufficient values to immediately commit to game or bid a suit at the one-level.[1]

The 2/1 game force does not apply to responses by a passed hand, or if there is an intervening call by an opponent. Other responses are as per Standard American methods in accordance with partnership agreement.

Game forcing auctions

The 2/1 auctions are: 1♦–2♣, 1♥–2♣, 1♥–2♦, 1♠–2♣, 1♠–2♦, and 1♠–2♥.

Variations

The following variations may be made by partnership agreement:

  • Some play that 1♦–2♣ is not game forcing
  • Some play that 2/1 is not absolutely game forcing and the pair can stop below game when responder rebids his suit. For example, 1♥–2♣; 2♥–3♣ may be treated as nonforcing.

1NT response

Because the two-level responses are stronger than in Standard American bidding, the response of 1NT is forcing for one round and is used (among other things) for weaker hands containing low-ranking suits. Since the 1NT response is forcing, hands with a three-card limit raise can start with 1NT and later jump-support partner. See Forcing notrump for additional details. Some pairs play a variant in which the 1NT response to 1♥ or 1♠ is semi-forcing.

Since opener has been forced to rebid on hands which he might otherwise have passed, he may have to rebid in a new suit with only three or even two cards.

Other features

Use of the 2/1 system usually implies (at least) the following additional agreements:

  • Five card majors, i.e. major suit openings require at least a five-card suit;
  • Either limit raises of major suit openings (i.e. the jump raise 1♠ – 3♠ or 1♥ – 3♥ shows a game-invitational hand with at least four-card support) or Bergen raises;
  • Inverted minor raises, in which a jump raise of a minor suit opening is a weak preemptive bid, while a single raise is strong and forcing for one round;
  • Jacoby 2NT, showing strong support with 4 or more cards;
  • Splinter bids;
  • New minor forcing;
  • Fourth suit forcing and artificial.

Examples

1♠ – 2♣
2♦ – 2♠
Forcing to game, with original spade support and good club suit. This is different from standard bidding, in which such a sequence would show about 10 points, and club suit could be semi-fake.

1♠ – 2♣
2♠ – 2NT.
Forcing to game, with balanced hand and a good club suit.

1♠ – 2♣
2♦ – 3♣
Forcing, unless the partnership has agreed that this is an exception to the "2/1 rule."

1♦ – 2♣
Forcing for one round only (as in Standard American), except in the variant of 2/1 where this sequence is game forcing as well.

1♣ – 2♣
Forcing for one round; 10 points or more with at least four clubs.

1♣ – 3♣
Weak; 9 points or less—sometimes much less—with at least five clubs.

1♥ – 2♥
Weak; 6-9 points with at least 3 hearts (unless Bergen raises are in use, in which case it shows precisely 3 hearts)

1♠ – 1NT;
2♣ – 2♠
Shows a weak hand, 6-9 points, with precisely two spades. Some also use this for an extremely weak hand (0-5) with three spades.

1♠ – 1NT;
2♣ – Pass
Shows a very weak hand, perhaps 5-7 points, with at least four clubs.

1♠ – 1NT;
2♣ – 2♦
Shows a weak hand, 5-9 points, with a long diamond suit.

1♠ – 1NT;
2♦ – 2♥
Shows a weak hand, 5-9 points, with a long heart suit.

1♠ – 1NT;
2♥ – 3♣
Shows a weak hand, 5-9 points, with a long club suit.

1♠ – 1NT;
2♣ – 2NT;
Shows 10-11 points without support for spades.

1♠ – 1NT;
2♣ – 3♠
Shows 10-11 points with 3-card support for spades.

1♠ – 3♠
Shows 10-11 points with at least 4-card support for spades.

1♠ – 1NT;
2♣ – 3♥
Shows 10-11 points with a long heart suit.

1♦ – 2♥
This is a jump response, and there are different ways of handling it. In Standard American, such a "jump shift" shows a very strong hand and is unequivocally forcing. However, since such hands do not occur with great frequency, it is more common today to use such a bid to show a weak hand with a long suit, unsuitable for defense. Another possibility is to play it as a "fit-showing jump", showing 8-10 points, a decent heart suit, and good diamond support.

gollark: I actually made CONS CONS all values in the program, for purposes.
gollark: ```lisp (let (qsort xs cont) (cond ((= xs '()) (cont '())) (true (do (let h (head xs)) (let t (tail xs)) (let part_result (partition_rec t (lambda (x) (< x h)) '(() ()))) (qsort (head part_result) (lambda (ls) (qsort (snd part_result) (lambda (rs) (cont (+ ls (list h) rs)))))) )) ))```Here is a sorting program.
gollark: Lisp is basically where you take a functional dynamically typed language and replace all the syntax with nested brackets.
gollark: As such, exactly 3 people will buy it.
gollark: The trouble with this is that despite being HIGHLY ethical, it costs many times what new generally much more powerful laptops do.

References

Notes
  1. Grant and Rodwell (2009), page 1.

Bibliography
  • Grant, Audrey; Rodwell, Eric (2009). 2/1 Game Force. Louisville, KY: Baron Barclay Bridge Supply. ISBN 978-0-939460-84-7.
  • Hardy, Max (2000). Standard Bridge Bidding for the 21st Century. SQueeZe Books. ISBN 978-1-58776-049-5. LCCN 00104457.
  • Hardy, Max (2002). Advanced Bridge Bidding for the 21st Century. SQueeZe Books. ISBN 978-1-58776-125-6. LCCN 2002104136.
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