Robot Bidding System #4 (2/1 Game Forcing)

1. Introduction

Since 2/1 is derived from SAYC, unless explicitly stated in this document, all other robot's bidding will stick to SAYC.

2. 2/1 Game Forcing Auctions

  1. After an one-level opening bid, a non-jump response in a new suit at the two level commits the partnership to bidding at least game.
  2. A game forcing hand should has at least 12+ HCP (Robot uses Rule 20 for testing) and typically 5+ cards long.
  3. On some occasion, responder's suit contains 4 cards, and on rare occasions the responder may need to make a minor suit response with a 3-4-3-3 distribution.
  4. 2/1 game forcing doesn't apply to a passed hand, or if there is an intervening call by an opponent.
Bid
 Description
1♦–2♣ For simplicity, it is excluded from 2/1 game forcing and sticks to the standard SAYC.
1♥–2♣ 12+ HCP, 4+ cards, game forcing.
1♥–2♦ 12+ HCP, 4+ cards, game forcing.
1♠–2♣ 12+ HCP, 3+ cards (in the rare case of 3-4-3-3), game forcing.
1♠–2♦ 12+ HCP, 4+ cards, game forcing.
1♠–2♥ 12+ HCP, 5+ cards, game forcing.

2.1 Opener's rebid after a two-over-one response to either major suit

Bid
 Description
Raise partner suit
 12+ HCP 4+ cards; or 14+ HCP with three cards support and a a high honour card, no rebid that is more descriptive.
Jump shift
 Splinter: a sound hand (14+ HCP), shortage in suit, 4+ card support for responder.
Non jump new suit at three level
 14+ HCP, 4+ cards; or 12+ HCP, 5+ cards.
New suit at two level
 4+ cards if 2H, 3+ good cards if 2D`
2NT
 12+ to 15- HCP or 18+ HCP, stoppers in both unbid suits and usually a balanced hand (5-3-3-2).
3NT
 15+ to 18- HCP, fast arrival not applicable.
Jump open suit
 15+ HCP, 6+ cards with excellent quality.
Rebid open suit
 5+ cards, no better descriptive can be made.

2.2 Responder's rebid

Bid Description
Opener rebid of the original major suit or 2NT
Game in the opening major
 12+ to 15- HCP, 3 cards support.
Three level in the opening major
 15+ HCP, 3 cards support, slam interest.
Opener rebids a lower ranking suit
Two level in the opening major 12+ to 15- HCP, 3 cards support.
Three level in the opening major 15+ HCP, 3 cards support, slam interest.
Game in the opening major 12+ to 15- HCP, 3 cards support, value concentrated in the suit of the response and in opener's suit, deny any control either by high card or shortness in unbid suits.
2NT
 12+ to 15- HCP, at most 2 cards in opener's major suit and stoppers in both unbid suit; or 18+ HCP and plan to show greater value if a 3NT raise from opener (3NT->4NT)
3NT
 15 to 17 HCP, at most 2 cards in opener's major suit
General
Rebid Own Suit
 6+ cards, deny opener's major suit support.
New suit
 4+ cards, deny opener's major suit support.

Notes:

  1. Hardy's book does not cover the section well, so we just implemented those explicitly stated. As the responder's rebid has a lot of possibilities, further enhancements will be done on that section with more reference materials and problem reports from users.

3. Raising Opener's Major Suit

  1. Raise of opener's major suit is the first priority.
 Bid
 Description
1♥–2♥,1♠–2♠ Simple raise. 5+ to 9- HCP, 3+ cards.
1♥–3♥,1♠–3♠ Limit raise. 9+ to 12- HCP, 4+ cards.
1♥–4♥,1♠–4♠ Jump to game. 2 to 8 HCP, 5+ cards, no support (AK) in side cards.
1♥/♠-2NT Jacoby 2NT. 13+ HCP, 4+ cards, game forcing.

4. Forcing Notrump

BId
 Description
1♥/1♠-1NT 5- to 12- HCP, may have 3 cards support in opener's major suit., force 1 round.

Notes:
  1. One notrump by a passed responder after a major suit opening bid is not forcing. It has the range of 5+ to 12 HCP, but denies a fit (at most 2 cards) for opener's major suit.

4.1 Opener's rebid after the Forcing Notrump

Bid
 Description
Rebid same suit at two level
 12+ to 15- HCP, 6+ cards.
Rebid same suit at three level
 15+ HCP, good 6+ cards.
Rebid same suit at four level
 Self sufficient suit, probably 10 winning tricks.
Reverse (1♥-1NT-2♠) 16+ HCP, more heart than spade, force 1 round.
1♠-1NT-2♥ 12 to18 HCP, 4+ cards.
1♠-1NT-2NT 18 to 19 HCP, 5-3-3-2 distribution.
Jump Shift
 3+ cards, 19+ HCP,  game forcing.
Rebid a minor (1♥/♠-1NT-2♣/♦) No other better choice, bid the lower rank minor with 3+ cards. 12 to 18 HCP, normally 3+ cards, but may be 2 cards in case of 4-5-2-2. When 1♥-1NT-2♣ was bid, responder will pass only with five clubs and a shortness in heart.


4.2.1 Responder's  rebids with minimum values (5+ to 9- HCP)

Bid
 Description
Support openers' major at the two level
 2+ cards. In case of 1♠-1NT-2♥, responder will take a "false preference" and return to spades with exactly 2 spades and 3 hearts, but can pass with three hearts and fewer spade.
New suit at the two level
 5+ cards. In case of 2♥, responder may also hold a doubleton spade and looking for the best major suit fit.
New suit at the three level without jumping
 Good 6+ cards, little value in side card.
Pass
 Deny any of the above,


4.2.2 Responder's rebid with maximum values (9+ to 12- HCP)

Bid
 Description
Jump to the three level in opener's suit. (After a rebid by opener at the two level in a lower ranking suit)
 3 cards. "Bad limit raise".
Jump to game in opener's suit. (After opener's suit is repeated at the two level or a jump shift)
 3 cards. "Bad limit raise".
2NT
 No more than two cards in opener's major suit and stoppers in both unbid suits.
Jump to the three level in a new suit
 6+ cards, good quality.
Raise opener's rebid suit
 Deny a fit in opener major suit. 4+ cards for hearts and 5+ cards for minor.
1♥-1NT-2♣/♦-2♠ Deny a stopper in spade and suggest a fit for the minor suit of opener's rebid.


5. New Minor Forcing (NMF)

When the opener opens with 1♣/1♦, after a response of 1♥/1♠, the opener rebids 1NT shows a balanced hand with 12-14 HCP. Responder bids a new minor has an invitation or better hand (10+/11 HCP). The bid is artificial and forcing, asking opener to describe further.

Responder may be:

  1. seeking a three card fit for a five card major;
  2. interested in opener's values (minimum of 12 to bad 13 HCP or maximum of good 13 or 14 HCP) in order to determine the appropriate level for play.

Opener will show one of the following:

  1. Minimum with 3 cards fit with responder's major suit by bidding the suit at 2 level.
  2. Maximum with 3 cards fit with responder's major suit by bidding the suit at 3 level.
  3. Minimum with 2 cards fit with responder's major suit by bidding 2NT.
  4. Maximum with 3 cards fit with responder's major suit by bidding 3NT.
  5. When responder's major suit is spade, opener should bid heart first if he has 4 cards.
  6. When responder's first major suit is heart, opener with minimum value will bid 2S to deny a stopper and 2NT if spade has stopper.

After opener first bid diamond and responder make a NMF of 2C, a rebid of diamond deny appropriate major suits and has 5+ diamonds.

Responder holds a weak hand with 4 cards in major and 6 cards in unbid minor suit is to jump to 3 level in that minor suit. Opener is required to pass and the auction ends.

5.1.1D-1H-1NT-2C

Bid
 Description
2D
 Deny 3 cards support and promise 5+ diamonds.
2H
 12-13 HCP, 3 cards support
2S
 deny 3 cards support or 5 diamonds or spade stopper.
2NT
 12-13 HCP, deny 3 hearts or 5 diamonds, has stopper in spades.
3H
 14 HCP, 3 cards support.
3NT
 14 HCP, deny 3 hearts or 5 diamonds, has stopper in spades.

5.2. 1C-1S-1NT-2D

Bid
 Description
2H
 4+ cards, may have 3 spades.
Respond
2S: 11-12 HCP, 5+ cards, deny 4+ hearts.
3S: 6+ cars, slam interest. Directly jump to 3S (invitational) or 4S (game play) instead of use NMF.
3NT: 13+ HCP, 5+ spades. (Opener correct to 4S if have 3 cards support)
2S
 12-13HCP, 3 cards support, deny 4 hearts support
3S
 14 HCP, 3 cards support, deny 4 hearts support.

5.3. 1D-1S-1NT-2C

Bid Description
2D
 5+ cards, deny 4 hearts or 3 spades.


Notes:

  1. Bidding other that those listed in the page may not be implemented for the robot.
  2. The page will be updated after robot has been modified and tested to be stable.
  3. The system is mainly based on Max Hardy's book "Standard Bridge Bidding for the 21st Century" ISBN 1-58776-049-5.

Last modified at 25-Dec-2013 by WeWeWeb.