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World Computer-Bridge Championship

Allowable Systems and Conventions

Explainable Bids


Allowable Systems and Conventions

In general, non-standard conventions and systems that require extensive programming by the opponents are not allowed.

Allowable Systems and Conventions are based on the ACBL General Convention Chart. More complex conventions, such as those appearing on the ACBL MidChart, are generally not allowed.  In addition, artificial opening one bids are not allowing.  The list of allowable conventions can be found under Allowable Conventions and Explainable Bids.

Explainable Bids

Given that a program may input the opponent's convention card before a match, the general guideline is 'limited' explainable bids (alerts).  Most bids will not be explainable, including some alterable/explainable conventional bids (in human play).  For example, transfers over 1NT opening bids, are alerted in human play but non-explainable in computer bridge play. Explainable bids are limited to uncommon conventional bids and are marked in Red on the Convention Card Spreadsheet.  Also see the Protocol Alerting Section at BlueChipBridge's website for a description of the information that can be given,

Conventions should be submitted using the Convention Card Spreadsheet

Allowable Conventions and Explainable Bids

Definition of "NATURAL":

Any offer to play in a suit for the first time: showing
  1. 3+ for Minors
  2. 4+ for Major
  3. 4++ for Overcall
  4. 5++ for Weak 2
  5. 6+ for Weak 3
A notrump opening or overcall if not unbalanced (generally, no singleton or void and only one or two doubletons).

See the Convention Card Spreadsheet for explainable bids (marked in Red).  For reference the items marked in Red on the Convention Card Spreadsheet are summarized below.  Please see the Convention Card for the official explainable items.
  NOT Explainable Explainable
NATURAL BIDS: about expected strength and shape unusual strength, shape or limitations, including opening 1C with 4-4-3-2 playing 5 card majors and 4 card diamond suit; Canapé
Stayman; Blackwood (4NT); Gerber/NT
artificial one bids NOT ALLOWED  

non-standard Ace asking bids

Drury; New Minor Forcing; 4th Suit Forcing; Lebonsohl; Weak Jump Shifts; Gambling 3NT; Inverted Minor Raises; Bergen raises; and other conventions not explicitly mentioned elsewhere

1. 1 NT

2. Higher NT
1. natural NT openings with a 3 hcp range and a minimum of 12 to 16 hcps; overcall within the 15-18 hcp range.

2. natural openings or overcalls

1. Conventional - NOT ALLOWED

2. Conventional - NOT ALLOWED

RESPONSES TO NT: a. Stayman (2C) asking for four card major and rebids
b. forcing suit-bids at the three-level
c. natural signoffs of 2D, 2H, 2S
d. transfers in all suits
e. 2S as Minor Suit Stayman
a. Stayman (2C) if other than asking for four card major and rebids
b. Notrump continuations after use of Stayman by responder which do not promise a major

c. all other artificial responses above 2C
d. non forcing suit responses at the three-level
OPENING SUIT BIDS: a. natural 2 Bids (weak)
b. strong/forcing and artificial 2C
c.. frequent very light (less than 10 hcp) third seat
d. 2C if not strong and forcing
e. natural 2D, 2H, 2S if not weak (Acol)
a. Flannery 2D or 2H, Benjamin 2D
b. Canapé System
RESPONSES TO SUIT BIDS: a. non-forcing 1NT response.
b. 1H or 1S response to 1C that may bypass a 4-card or longer diamond suit
c. 2/1 game force
d. negative or waiting 2D/strong 2C or 2NT/strong 2
e. 2NT/2 level openings asking for clarification. Preemptive jump raises
f. non-forcing 2NT/1-bid by UPH
g. 1NT rebid if strong or may bypass majors
a. 1NT responses to a major that are unusual, such as 1H-P-1NT showing spades
b. non forcing suit bids by UPH
c. natural jump shifts not game forcing and; conventional jump shifts
d. 1NT/1C or 1D not denying four spades or four hearts
e. responses to explainable opening 2 bids
f. Bergan raises
OPENER'S REBIDS: a. two of a minor after a forcing 1NT or semi-forcing 1NT that could be three cards
b. 1NT rebid if strong or may bypass majors
a. artificial or asking Bids; Canapè
b. non-natural game tries
OTHER CONSTRUCTIVE CALLS: a. preemptive jump raise/Double
b. limit or forcing jump raise over Dbl
DEFENSIVE BIDS: a. jumps to 2NT or any 4-level or higher NT bid that is unusual.
b. 1NT overcall by a passed hand that is unusual.
c. non-jump Unusual NT
d. very light overcalls (fewer than 6 hcp)
e. weak jump advances
f. jump overcalls which are intermediate or better
jump overcall indicating at least 5-4 distribution in two known suits and responses thereto
CUEBIDS: most meanings of cuebids.
a. an offer to play in a suit or denomination named naturally by an opponent
b. very unusual, for example: 1S-2H-Pass-2S, where 2S is a transfer to clubs
Not Explainable Explainable
Usual Takeout
Lead Directing Double
Unusual Penalty Doubles
Lead Directing Double for a suit other than the one doubled

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