Bridge

Fourth Suit Forcing

Artificial game-forcing (or game-invitational) call after three natural suits have been bid.

sequence

1x — 1y — 1z — 2w (w = the last unbid suit)

how it works

When opener and responder have shown three suits in the first three rounds, the fourth suit is bid artificially by responder to force further description from opener. Doesn't promise length in the 4th suit — just says 'we have game values, please keep bidding.' Opener rebids naturally: 3-card support for responder's major, own extra length, a stopper in the 4th suit for NT, or the 4th suit actually held.

used in 6 places

2♣2♣
after 1D — P — 1H — P — 1S — P
2♥2♥
after 1D — P — 1H — P — 1S — P — 2C — P
2NT2NT
after 1D — P — 1H — P — 1S — P — 2C — P
3♣3♣
after 1D — P — 1H — P — 1S — P — 2C — P
3♦3♦
after 1D — P — 1H — P — 1S — P — 2C — P
3♠3♠
after 1D — P — 1H — P — 1S — P — 2C — P