Fourth suit forcing is a bridge convention and it is used to help decide the best contract. It is a bid used by the responder if they have 11+ points and is used if:
- Three suits have already been bid (hence the name)
- You don’t have a fit (8+ cards in a suit) with your partner
- You DON’T have a stopper in the remaining (4th) suit.
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 “I don’t have a stopper in this suit, what else do you have?”
If the declarer’s answer is “yes, I do have a stopper in that fourth suit” then they can bid No Trumps.
Here is an example to help explain:
Responder holds: Spades K J 8 5 2, Hearts 7 4 3, Diamonds A 6, Clubs A Q 7
Opener bid 1D, responder bid 1S. Opener rebid 2C.
This hand has enough points for a NT bid, but doesn’t have a stopper in hearts. Three of the four suits have now been bid, so if responder bids the remaining suit (hearts in this case) the bid is asking the opener if they stopper in that suit. If they do, they bid NT. If they don’t have a stopper in hearts they must make another bid. As the name implies, the bid of the fourth suit is a forcing bid and the opener must bid again.
Remember that 4th Suit Forcing should only be used if you have 11+ points. You can use 4th suit forcing at the 3 level if you have 13+ points as you know you and partner have at least 25 points (partner held the 12 points or the equivalent to open) and are looking bid for game.
With stopper in fourth suit
- If the opener has a stopper in the fourth suit but just a minimum opening hand (12 -13 points) then s/he should bid 2NT
- If the opener has a stopper AND 14+ points then s/he can bid 3NT as they know there are enough for game. (14 + partner’s minimum of 11)
Without Stopper in Fourth Suit
- If the opener has extra length in either their first or second bid suits they should rebid them. A rebid of the first suit would show 6 cards and a rebid of the second suit would show 5 cards.
- With 3 card for responder’s original suit and minimum points, bid two of the responder’s suit.
- With 3 card support in responder’s original suit AND 13+ then make a jump bid.
The main aim of answering a 4th Suit Forcing bid is tell your partner something that they don’t already know, if possible.
Here are a few examples:
Opener has Spades – 6, Hearts – K 5 2, Diamonds, A Q 9 5 3, Clubs K 10 7 3.
Opener bid 1D, Responder bid 1S, Opener rebid 2C, Responder bid 2 H. The 4th suit forcing bid by responder shows 11+ points
Opener has a stopper in hearts but only minimum points (12), so bids 2 NT. Responder can rebid 3NT with 13+ points.
Opener has Spades – 8, Hearts – K 9 4, Diamonds – A Q J 7 3, Clubs K Q 6 5. The bidding went as before in example 1. But this time opener holds 15 points and so can go straight to 3NT
Opener has Spades – J 6 3, Hearts – 8, Diamonds – A Q J 7 3, Clubs – K Q 9 4. Bidding as before. Opener doesn’t have a stopper in hearts but can rebid 2S to show 3 cards in spades. It’s possible responder might hold 5 spades. They already know opener doesn’t have four, otherwise opener would have supported their first bid of 1S.