Fourth Suit Forcing

What is Fourth Suit Forcing?

Fourth suit forcing is a bridge convention. It is used to help you find the right contract, including finding 5-3 major suit fits and finding a stopper for No Trumps.  It is used when you are responder and have 11+ points and:

  • Three suits have already been bid (hence the name)
  • You don’t already have a major suit fit (8+ cards in a suit) with your partner
  • You want to find out more information about partner’s hand

If your opening partner changes suit again after your change of suit you might not have enough information to decide on the contract.  This is especially the case if you, as responder, hold a 5 card major suit. (See example below). At this stage (3 suits already bid) a bid of the fourth suit doesn’t mean that you hold good cards in the suit and want to bid it.  It is a conventional bid which means “ tell me something more about your hand partner?”

The opener then replies to tell the responder something more about their hand such as:

1)    Bidding the responder’s first suit shows three cards held in that suit

2)     Re-bidding their own second suit shows that they hold 5 cards in that suit

3)     Re-bidding their own first suit shows they hold 6 cards in that suit

4)     Bidding No Trumps shows that they hold a stopper in the fourth suit

5)     If they have none of the above, they may need to rebid their first suit with only 5 cards.

4th Suit Forcing Example

You are south and you hold this hand:

 S:  8 7
 H: K Q T 7 4
D: A J 5
 C:  K T 3

The first three bids went like this

North  East   South  West
1D  Pass   1H  Pass
1S  Pass     ?

You think that 3NT is probably the right contract.  However, if you bid that now you might miss an 8 card fit in hearts if partner holds 3 cards.  Their bidding so far show they probably hold 5 diamonds and 4 spades.  It is possibly they hold 3 hearts and just one club.  But we won’t know unless we ask.  This is where we use 4th suit forcing.

We bid 2 Club.s  This doesn’t mean we want to say anything about our own clubs, just that we are asking partner to bid again and tell us more about their hand.  Then we have the information we need to choose between a 3NT contract or a 4 Hearts contract.

Some possible responses to a fourth suit forcing bid

North East South West
1D Pass 1H Pass
1S Pass 2C Pass
2H Pass ?

Here, partner has told us that they hold 3 hearts.  This means we have an 8 card major fit so we can jump bid to 4 hearts.

North East South West
1D Pass 1H Pass
1S Pass 2C Pass
2D Pass ?

Here, partner has rebid their diamonds.  This tells us that they have 6 diamonds, or possibly 5 diamonds and nothing else worth showing.  In this case we would bid 3NT.

Example – Opener’s response to 4th Suit Forcing

4th Suit ForcingNow, imagine you are OPENER.  So far you have bid diamonds and clubs and partner has just bid the fourth suit, asking you to further describe your hand.

North East South West
1D Pass 1S Pass
1C Pass 2H Pass

Our bidding so far has told partner that we hold at least 5 cards in diamonds and at least 4 cards in clubs.  We don’t hold 3 spades, so can’t support partner’s spades bid.  We there for rebid our clubs, telling partner that we hold 5 clubs.

Further Examples

There are lots more examples of 4th suit forcing on the No Fear Bridge UK site, including a handout and a quiz, to help you understand and practice this topic.  Just CLICK HERE to take your trial membership right now.