Double Club System

Auctions starting 1C, 1D; 1S

What has been shown?

Opener has an unbalanced hand with no suit longer than clubs and a spade suit of a least 4 cards. Opener will bid this way with 4=4=1=4 or 4=4=0=5 shape, so he may have a 4-card heart suit as well.

Responder is unlimited at this stage, though he could have nothing. If he has some values, he may have 6-11 hcp with a 4-card major (but no 5-card major), or he may have a strong hand (12+ hcp) with diamonds as the longest suit.

Strategy

Responder bids 2D if he has the natural and strong diamond hand, even if he has support for one of opener's suits. With a weak hand (less than 6 hcp, or less than 8 hcp with no 4-card major) responder can pass or give preference to clubs. Otherwise responder will have a 4-card major and 6-11 hcp for his bid of 1D. He should support spades if he has that suit, or bid 1NT or 2H if having 4 hearts.

Note: It is possible that responder has 6-7 hcp and a hand with clubs or diamonds as the only 4-card or longer suit. In that event he should not rebid 1NT, since that rebid promises a 4-card heart suit. He must either pass 1S or give preference to 2C.

Continuations

pass
Preference of spades. Not showing any particular strength and may have absolute zero.
1NT [Alert]
Shows 6-9 hcp and a 4-card heart suit. This bid should be alerted, even though it is natural and non-forcing, since the opponents need to be informed that it guarantees a 4-card heart suit. Opener may pass or continue with any natural bid. He will obviously raise hearts to the appropriate level if he also has a 4-card heart suit. Responder need not be balanced to make this bid: he will always bid 1NT if he has 4 hearts and no fit for clubs or spades.
2C
Preference of clubs. Not showing any particular strength and may have absolute zero.
2D
Shows 12+ hcp and a natural diamond suit.
2H
Shows 10-11 hcp and a 4-card heart suit.
2S
A raise of spades. Shows 9 losers (say 6-9 hcp) and a 4-card spade suit.
3C
A raise of clubs. Showing at least 4-card support but less than 8 hcp.
3S
A strong raise of spades. Shows 8 losers (say 10-11 hcp) and a 4-card spade suit.

Author: Chris Burton
Gravesend Bridge Club