Double Club System

Auctions starting 1C, 2C

What has been shown?

Opener has either an unbalanced hand with no suit longer than clubs or a balanced hand with 17+ hcp.

Responder has a 4-card or longer club suit and either 8-11 hcp or 14+ hcp, and denies a 4-card major suit. Responder will not have a hand of 12-13 hcp (he should have raised clubs by bidding 3C or an artificial 2NT if he has 12-13 hcp).

The auction is forcing to at least 3C.

Strategy for Opener

An unbalanced opener assumes that responder has 8-11 hcp with club support and bids accordingly, so that light or minimum opener bids 3C as a sign-off. When opener has 15+ hcp he can make a try for game by bidding a stopper, but (because 15 + 8 = 23, which is 2 hcp short of the 25 hcp we want for game) neither partner can bid beyond 3C unless having at least 2 hcp more than the minimum shown so far.

If opener has a balanced hand with 17+ hcp he rebids 2NT, which is obviously game-forcing.

Strategy for Responder

When responder has 8-11 hcp he lets the bidding develop normally, accepting a sign-off from opener when it occurs. When responder has 14+ hcp he makes a further try over opener's eventual sign-off,

Continuations by Opener

2D/H/S
Game-invitational and stopper-showing. Showing an unbalanced hand with 15+ hcp. Responder should co-operate by showing a stopper in return, or bidding no trumps if all suits are stopped, but responder may not bid beyond 3C unless having 10+ hcp and opener may not bid beyond 3C unless having 17+ hcp. That ensures that we have at least 25+ hcp before we bid above 3C.
2NT
Forcing. A balanced hand of 17+ hcp (with no upper limit). Opener may have a 5-card major so, if responder has a 3-card holding in either major, his rebid should leave room for opener to show a 5-card major suit if he has one.
Note: Refer to the linked notes on this bid to find out how a 5-3 major suit fit can be found and how opener shows extra strength if he has considerably more than 17 hcp.
3C
Opener is weak or even light, with a maximum of 14 hcp. Responder must pass if having 8-11 hcp, since a good game contract is unlikely. If responder has 14+ hcp, he should make a game try by bidding a new suit to show a stopper, or he should bid 3NT if having stoppers in all suits. The auction can end in 4C if a stopper is absent and 5C is out of reach.
3D/H/S
Splinter bid, showing shortage in the bid suit and interest in a slam. Responder should correct to 3NT if having a double stopper in the splinter suit.
3NT
Possibly a gambling bid with an unbalanced hand. Responder should pass unless a club slam appears to be a better prospect.

Author: Chris Burton
Gravesend Bridge Club