Double Club System

Auctions starting 1NT, 2C; 2H/S

What has been shown?

Opener has shown a balanced hand with a 5-card major. He will not usually have a second 4-card suit, and certainly not a 4-card holding in the other major.

Responder is either interested in a major suit fit or wishes to play in a diamond part score. If his intention was to play in 2, that is not now possible. He can still choose to play in 3, but he may instead decide to pass and play in opener's 5-card major.

Continuations by Responder

pass
Responder wishes to play in a part-score in opener's major suit.
2 (over 2)
Natural and game-invitational (non-forcing). Responder does not have a 3-card or longer heart suit. Responder shows a 4-card spade suit and game-invitational values, and opener is invited to pass with 3-card spade support if he refuses the game invitation.
2NT
Natural and game-invitational (non-forcing). Responder invites game in no trump. He was obviously looking for a fit in the other major. If opener can accept the invitation and has 3 cards in the other major, he should bid the other major on the way to 3NT, so that responder can choose the major suit game if there is a 5-3 fit.
3/
Natural and forcing, showing a 5-card suit. Responder was seeking a 5-3 or 4-4 fit in the other major. He now seeks a 5-3 fit in the bid minor suit, with slam interest if a fit is found. Opener bids 3NT with only a doubleton in support. Any other bid by opener shows 3-card support.
3/
An invitational raise, accepting opener's suit as trumps.
3 (over 2)
Artificial agreement of spades as trumps and suggesting interest beyond game. Opener should cue bid a feature if maximum, or a particularly suitable minimum, or bid 3NT with an unsuitable minimum.
3 (over 2)
Artificial agreement of hearts as trumps and suggesting interest beyond game. Opener should cue bid a feature if maximum, or a particularly suitable minimum, or bid 3NT with an unsuitable minimum.
3NT
To play.
4/
To play.
4NT
Natural and non-forcing: Invitational to slam.
Note: If wishing to use RKB you must first agree trumps by bidding the other major suit as an artificial agreement.

Author: Chris Burton
Gravesend Bridge Club