4th Suit Forcing

Fourth suit forcing is a partnership agreement that allows responder to create a new forcing bid at his/her 2nd turn to bid. The fourth suit forcing convention, is a bid by either player in the fourth (unbid) suit and is conventional (i.e. does not promise any particular holding in the 4th suit bid).

It implies that the bidder has no good bid, but nonetheless has something of value, and wishes to continue searching for a contract. It allows the bidding to return to their partner, and asks them to find a bid or to further describe his/her hand.

This convention is adopted by the vast majority of partnerships that play bridge.

The fourth suit forcing convention is particularly useful on strong (game-going hands) on which no natural forcing bid is available.  It is a type of game trial bid.

 

Example: A typical 4th suit forcing situation is as follows:

 South

North

 

North Holds

♠ A Q 8 6 2

♥ 8 4 3

♦ Q 7

♣ A 6 5

1♦

1♠

 

2♣

?

 

After 2♣, North can see there are likely to be sufficient points for game, but he has no good bid:

·         He has shown his spade suit fully. To rebid spades would imply a longer or stronger suit than he has. They are not good enough for a 3♠ rebid.

·         He cannot bid to support either minor suit because his holding in both is inadequate.

·         He cannot bid no trumps because it implies a Heart stop, which he lacks.  If he bids no trumps they will probably end up in 3 NT and a heart lead will be an obvious lead: they may well lose 4 or even 5 heart tricks immediately.

North is also unable (or very reluctant) to pass because with three suits bid and around 24-26 + high card points, he feels that there is a good chance some game contract could be viable. But he doesn't have a good bid to make.

North instead bids the fourth suit (fourth suit forcing)—2♥—to indicate that he believes they have values for game, and to indicate that he lacks the stop in the fourth suit needed for no-trumps, and hasn't got a sensible bid in any of the other suits.

Responses

Opener responds to the fourth suit forcing by (in prioritised order):

  1. Raising of responder's 1st bid suit with 3-card support,
  2. Bidding notrump with values in the fourth suit,
  3. Raising the 4th suit with 4-cards in that suit,
  4. Making the most natural rebid possible, lacking any of the above.