Double Club System

Auctions starting 1D, 1H/S

What has been shown?

Opener has an unbalanced hand with no suit longer than diamonds or (in 1st/2nd position) a balanced hand with 5-card diamonds and less than 14 hcp. In 3rd/4th position a balanced opener may have only a 3-card or a 4-card diamond suit.

Continuations

1 (over 1)
Opener has an unbalanced hand with a 4-card or longer spade suit and a diamond suit that is probably longer. If 1D was a 3rd/4th position opening bid, opener may have a 4-4-3-2 balanced hand of 11-13 hcp with diamonds and spades, but he would pass rather than open with this shape in 1st/2nd position.
1NT
Opener has a balanced or semi-balanced 11-13 hcp, with a 5-card diamond suit if he opened in 1st/2nd position.
2
Opener has 4+ clubs and 4+ diamonds and is unbalanced.
2
Opener probably has 6+ diamonds and no other suit, although he may have 5 diamonds and 4 hearts if responder's bid was 1S.
2 (over 1S)
A natural and forcing reverse.
2NT
Conventional and forcing. Shows 6+ diamonds and wishing to be in game unless responder is minimum. Responder's only possible sign-off is to bid 3D.
3
Not defined. Bid 2NT instead.
3NT
Conventional and forcing. Shows game values and good support for responder's suit, agreeing it as trumps. No sinleton or void, or eles opener would have splintered.
jump new suit bids
Natural and forcing.
double-jump new suit bids
Splinter in support of responder's major suit.

Author: Chris Burton
Gravesend Bridge Club