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GIB System Notes

We have created a standard convention card for GIB. Click here to see GIB's convention card.

In general, the GIB robots on BBO use the 2/1 system described below. You can click on any of GIB's bids for an explanation, and pause your mouse over a bid you plan on making to see how it will understand it.

Please drop us a line at support@bridgebase.com if you spot any errors in this document.

Overview

2/1 Game Force with 5 card majors, strong NT, strong (17+) jump shift, weak 2 bids and a strong artificial 2C.

Gib leads 4th best when it leads from a long suit, and standard honor leads (K from AKx, A from AK doubleton). Uses standard signal for count (not attitude); however, if you lead a high honor on the opening lead, it will give attitude. Discard are usually in a short suit in a trump contract if it has trumps left, otherwise in a long suit that it thinks it can afford to shorten.

HCP vs Total Points

Gib uses both old fashioned HCP (A=4,K=3,Q=2,J=1)) and “Total points” (HCP+3 for void, 2 for singleton, 1 for doubleton, but short suits containing J or higher are reduced by 1 point). It sometimes uses “8421” points when cuebidding (A=8,K=4,Q=2,J=1). It will usually force to game if it thinks it has 25 Total Points between the two hands.

Basic Approach

Opening bids

Responses and Rebids

• Opening jump rebid (1c-1any-3c for example) promises 6+ card, 17-20 HCP

• Opening major rebid after 2/1 response does not promise 6 cards in the suit.

• Jacoby 2NT

• Raising responder's suit usually promises 4 cards, but will occasionally raise with only 3

Competitive Auctions

• 1-level overcall shows 5+; 8-17 HCP; 9-19 TP. However, might overcall 1-major with decent hand and a strong 4-card suit.
  

• GIB uses the law of total tricks.

• Takeout doubles to 4H

• Negative X and Responsive X up to 3S, Support X up to 2H (GIB may do support X with Kx).

• Weak jump overcalls (aggressive, 3-9 HCP, no allowance for vulnerability)

• Cappelletti when opponents open 1NT (aka Hamilton)
  

• Lebensohl after 1NT, double of weak 2, and after reverse.
  

• Michaels cue bid

• Unusual NT (GIB only does Unusual NT with intermediate hands, xx-KQxxxx KQxxx for example))

• Unusual versus Unusual, lower cue = limit raise or better (GIB does UVU, but doesn't alert it with this name)

• Sandwich 1NT = Strong (15-17) by unpassed hand, 5-5 in other 2 suits by passed hand
  

• Truscott after partner's opening doubled (aka Jordan)
  

• Western Cue bid (GIB doesn't alert western cue with this name)

Other conventions and treatments

• Fourth Suit Forcing (Game forcing except for 1C-1D-1H-1S)

• New minor forcing (one-way)

• Roman Key Card Blackwood. GIB doesn't like to use Gerber, but it will respond appropriately

• Strong (Soloway) jump shifts by unpassed hand, fit jumps by passed hand.
  

Notes

• GIB is quite aggressive at the faster (basic robot) settings. It likes to redouble, so careful with those sacrifices.

• Vulnerability does not affect opening/overcall decisions. GIB seems to consider vulnerability and form of scoring only when thinking about leaving in a double for penalties, and other competitive decisions (they get used when performing simulations and estimating the expected value of different outcomes)
  

Conventions that GIB does not play

• Drury, reverse Drury

• Gambling 3NT

• Namyats

• Bergen or Reverse Bergen Raises

• DONT

• Puppet Stayman

Two-way Game Tries

After a single raise of a major suit, GIB plays two-way game tries.

• The next step (1H-2H-2S, 1S-2S-2NT) is a short-suit game try, showing unspecified shortness. Responder can bid the next step above that (2NT or 3C) to ask where the shortness is. Opener bids the short suit, or bids his major if the short suit is one of the step suits.
• Any other bid below 3 of the major is a long suit game try, at least a 3-card suit with some honors. After 1H-2H, 2NT is a LSGT in spades (since 2S would be a short-suit game try).
• 3 of the major is a general strength game try, showing about 17 points with no singleton or void (GIB rarely makes this bid, since this would probably be a 1NT opener).

Roman Keycard Blackwood (RKCB)

RKCB is a 4NT bid that, unlike regular Blackwood, asks for "keycards" instead of Aces. There are always 5 keycards - the 4 Aces plus the King of the agreed trump suit. If no trump suit has been clearly agreed, the King of the most recently bid suit is typically counted as the 5th keycard.

Responses to 4NT RKCB 0314:

• 5C  0 or 3 keycards
• 5D  1 or 4 keycards
• 5H  2 or 5 keycards, but no Queen of the agreed suit
• 5S  2 or 5 keycards plus Queen of the agreed suit
• 5NT An even number of keycards plus an unspecified void
• 6x An odd number of keycards with a void. If 6x is below 6 of the agreed suit then the void is in the suit bid. If 6x is a bid in the agreed suit then the void is in an unspecified higher-ranking suit.

After the 5C and 5D responses, the 4NT bidder can bid the next step that is not a signoff in order to ask for the Queen of the agreed suit. Then:

• Bidding the agreed suit at the cheapest level denies the Queen of the agreed suit.
• Bidding a new suit promises the Queen of the agreed suit plus the King of the suit bid.
• Bidding 5NT promises the Queen of the agreed suit and denies a side King that can be shown below 6 of the agreed suit.

A subsequent 5NT bid by the 4NT bidder (regardless of whether or not an ask for the Queen of the agreed suit has taken place) asks for specific Kings. The 5NT bid promises that all of the 5 keycards and the Queen of the agreed suit are accounted for. Then:

• The responder to RKCB is entitled to bid a grand slam if he thinks that 13 tricks rate to be available.
• If the responder to RKCB has a King that is lower-ranking than the agreed suit, he should bid that suit at the 6-level. If he has more than one such King, he should bid his lowest-ranking King.
  
• Otherwise the responder to RKCB should bid 6 of the agreed suit.
  

DOPI after interferences:

• Interferences after 4NT (whether RKCB or regular Blackwood) is handled by the DOPI convention.
• Double with 0 keycard (or ace, playing regular blackwood), pass with 1 keycard (or ace, playing regular blackwood).

After a 1N opening bid

• 2C     Stayman (promises at least one 4-card major unless inviting 3NT).
• 2D    No 4-card major
•  2H/2S    Invitational with 5 of the suit bid and 4 of the other major
•  2NT        Invitational (does not promise a 4-card major)
•  3C/3D    5+ card suit. Forcing to game
•  3H/3S    Smolen (forcing to game with 4 of the suit bid and 5 of the other major)
•  4NT         Invitational to 6NT.
• 2H    4 hearts (could also have 4 spades)
• 2S         Invitational with 4 spades
• 2NT        Invitational, denying 4 spades
• 3C/3D    5+ card suit. Forcing to game
• 3H         Invitational
• 3S         Artificial slam try with at 4+ hearts, usually balanced
• 4C/4D   Splinters (singleton or void in the suit bid, 4+ hearts, interest in slam)
• 4NT        Invitational to 6NT
• 2S    4S (denies 4 hearts)
•  2NT      Invitational (does not promise 4 hearts)
•  3C/3D   5+ card suit. Forcing to game
  
•  3H        Artificial slam try with 4+ spades, usually balanced.
•  3S        Invitational
•  4C/4D/4H    Splinters (singleton or void in the suit bid, 4+ spades, interest in slam)
• 4NT        Invitational to 6NT
•  2D    Jacoby Transfer Bid (promises 5+ hearts). Opener would normally bid 2H, but can superaccept with a maximum and 4-card heart support. After 2H:
• 2S        5+ hearts, 5+ spades, invitational to game.
• 2NT        Exactly 5 hearts, invitational to game.
• 3C/3D    5+ hearts, 4+ card suit. Forcing to game.
  
• 3H        Invitational with 6+ hearts
• 3NT        Exactly 5 hearts. Choice of games (4H or 3NT).
• 3S/4C/4D    Splinters (6+ hearts, singleton or void in the suit bid,  interest in slam)
• 4H        6+ hearts, no singleton or void, mild slam interest
• 4NT        Exactly 5 hearts. Invitational to 6H or 6NT
• 5NT        Choice of slams (6H or 6NT)
•  2H    Jacoby Transfer Bid (promises 5+ spades). Opener would normally bid 2S, but can superaccept with a maximum and 4-card spade support. After 2S:   
• 2NT        Exactly 5 spades, invitational to game.
• 3C/3D    5+ spades, 4+ card suit. Forcing to game.
• 3H        5+ spades, 5+ hearts. Forcing to game.
• 3S        Invitational with 6+ spades
• 3NT        Exactly 5 spades. Choice of games (4S or 3NT).
• 4C/4D/4H    Splinters (6+ spades, singleton or void in the suit bid,  interest in slam)
• 4S        6+ spades, no singleton or void, mild slam interest
• 4NT        Exactly 5 spades. Invitational to 6S or 6NT
• 5NT        Choice of slams (6S or 6NT).
•  2S    Minor Suit Stayman (Usually at least 54 in the minors, forcing to game)
• Opener would normally bid a 4+ card minor if he had one, but can bid 2NT with 3343 or 3334 distribution.
•  If responder's next bid is 3 of a major, he is promising a singleton or void in that suit, but not necessarily slam interest
•  2NT    Minor Suit Transfer (Promises 6+ clubs. Opener must bid 3C)
• If responder's next bid is 3 of a new suit, he is promising a singleton or void in that suit, but not necessarily slam interest
•  Responder's 3NT rebid is a mild slam try (usually balanced).
•  Responder's 4NT rebid is RKCB
•  3C    Minor Suit Transfer (Promises 6+ diamonds. Opener must bid 3D)
•  If responder's next bid is 3 of a new suit, he is promising a singleton or void in that suit, but not necessarily slam interest
•  Responder's 3NT rebid is a mild slam try (usually balanced).
•  Responder's 4NT rebid is RKCB
•  3D/3H/3S    Singleton or void in the suit bid, at least 4 cards in the other 3 suits, no 5card major, forcing to game.
•  3NT    Signoff
•  4C    Gerber
•  4D    Texas Transfer (Promises 6+ hearts, opener must bid 4H)
•  New suit rebid by responder is a cuebid.
•  4NT rebid by responder is RKCB.
•  4H    Texas Transfer (Promises 6+ spades, opener must bid 4S)
•  New suit rebid by responder is a cuebid.
• 4NT rebid by responder is RKCB.
•  4NT    Invitational to 6NT
•  5NT    Invitational to 7NT

After a 2N opening bid

•  3C Stayman (promises at least one 4-card major)
•  3D   No 4-card major
•  3H/3S  Smolen (forcing to game with 4 of the suit bid and 5 of the other major)
•  4C/4D  5+ card suit. Interest in slam
•  4H/4S  Signoff bids
•  4NT    Invitational to 6NT
•  3H    4 hearts (could also have 4 spades)
•  3S      Artificial slam try with 4+ hearts
•  3NT    Choice of games (4S or 3NT). Promises 4 spades.
•  4C/4D  5+ card suit. Interest in slam
•  4NT     Invitational to 6NT
•  3S   4 spades (denies 4 hearts)
•  3NT    Signoff (promises 4 hearts)
•  4C/4D 5+ card suit. Interest in slam.
•  4H      Artificial slam try with 4+ spades
•  4NT     Invitational to 6NT
•  3D    Jacoby Transfer Bid (promises 5+ hearts). Opener would normally bid 3H, but can superaccept with a maximum and 4-card heart support. After 3H:
•  3S       5+ hearts, 5+ spades, interest in slam
•  3NT     Exactly 5 hearts. Choice of games (4H or 3NT)
•  4C/4D  5+ hearts, 4+ cards in suit bid, forcing to game
•  4H       Mild slam try with 6+ hearts
•  4NT     Exactly 5 hearts. Invitational to 6H or 6NT
•  5NT      Choice of slams (6H or 6NT)
•  3H    Jacoby Transfer Bid (promises 5+ spades). Opener would normally bid 3S, but can superaccept with a maximum and 4-card spade support. After 3S:
•  3NT     Exactly 5 spades. Choice of games (4S or 3NT)
•  4C/4D  5+ spades, 4+ cards in suit bid, forcing to game
•  4H       5+ spades, 5+ hearts, choice of games (4H or 4S)
•  4S        Mild slam try with 6+ spades
•  4NT     Exactly 5 spades. Invitational to 6S or 6NT
•  5NT     Choice of slams (6S or 6NT)
•  3S   Minor Suit Stayman (usually at least 54 in the minors, forcing to game)
•  Opener would normally bid a 4+ card minor if he had one. Otherwise he would bid 3NT.
•  If responder's next bid is 4 of a major, he is promising a singleton or void in that suit
•  3NT  Signoff
•  4C  Gerber
•  4D   Texas Transfer (Promises 6+ hearts, opener must bid 4H)
•  New suit rebid by responder is a cuebid.
•  4NT rebid by responder is RKCB.
•  4H  Texas Transfer (Promises 6+ spades, opener must bid 4S)
•  New suit rebid by responder is a cuebid.
•  4NT rebid by responder is RKCB.
•  4NT   Invitational to 6NT
•  5NT   Invitational to 7NT

Soloway Jump Shifts

GIB plays Soloway Strong Jump Shifts by an unpassed hand in uncontested auctions. A jump shift shows one of the following types of hands:

1. Strong rebiddable suit, 17+ total points, 4+ controls (A=2, K=1), no side 4-card suit
2. Solid suit, 17+ total points, 4+ controls, may have a side 4-card suit
   
3. Rebiddable suit, 18+ HCP, 4+ controls, 5332 or 6322 shape.
4. Rebiddable suit, 17+ total points, 4+ controls, 4-card support for opener's suit

Opener can rebid his suit to show 6+, raise responder or bid RKC Blackwood with 3+ support, bid a side suit to deny support and show least KQ in the  suit, or bid NT at the cheapest level to show any other hand.

Jump shifter shows which type of hand it had with its next bid:

• With types 1 or 2, it rebids its suit, jumping to game with a minimum and solid suit (note that it never shows the side suit in type 2).
• With type 3, it bids NT or raises NT to game.
• With type 4, it raises opener's suit with no side shortness, or bids its short suit (this is why it can never show its own side suit – a new suit is a splinter in support of opener).