Double Club System

Auctions starting 1C, 1D; 1S, 1NT

What has been shown?

Opener has an unbalanced hand with clubs and spades. He will have 5+ clubs unless his shape is precisely 4=4=1=4 (singleton diamond). It is also possible that opener's shape is 4=4=0=5, so he may yet have a 4-card heart suit as well as clubs and spades.

Responder has shown 6-9 hcp and a 4-card heart suit (but no 5-card major).

Strategy

Opener is pretty much in a position to pick or suggest the final contract.

Continuations

pass
Happy to play in 1NT.
2C
To play, although responder may correct to spades if holding three spades but only a singleton or void club.
2D
An artificial fourth suit bid (hearts has been shown by responder's 1NT bid). Asking responder for a stopper in diamonds. Responder should bid 2NT or 3NT if having a stopper, otherwise return to one of opener's suits.
2H
To play. A minimum hand with heart support, but possibly only a 3-card suit.
2S
A natural reverse, showing a strong hand with a 5-card spade suit and longer or better clubs. Forcing for one round.
2NT
A natural invitation to game, showing no worries about the diamond suit.
3C
A strong but non-forcing rebid. Shows a 6-card club suit as well as 4-card spades.
3H
A raise of hearts, promising 4-card support and (because opener is now known to be three-suited) a diamond singleton or void. Responder should bid game unless he has wasted values in diamonds. Note that there is no need for a 3D splinter bid in this sequence, so it is better to bid 3H which does not allow the opponents a cheap double to suggest a diamond save.
3NT
To play, showing no worries about the diamond suit.

Author: Chris Burton
Gravesend Bridge Club