Fourth suit forcing

The hand that has nowhere to go

None of the natural bids works:

• 2♥: shows five hearts and about 10 points. You have 13, and partner will pass.
• 3NT: you have no club stopper and no idea whether partner does.
• 3♦: supports a suit partner may hold only four of, and buries the hearts.
• 2♠: you hold two of them.

2♣ is the fourth suit. Played as forcing, it keeps the auction going at a low level and asks partner to describe their hand further.

What opener must answer

In priority order:

1. A stopper in the fourth suit? Bid notrump, at the cheapest level with a minimum, jumping with extras. A club stopper is often what responder is hoping to hear about.
2. Three-card support for responder's major? Bid it. A 5-3 major fit usually plays better than notrump.
3. Extra length? Rebid your own first suit with six, or show a fifth card in the second suit.
4. None of the above? Bid the cheapest of whatever is left and let responder place the contract. You have a game force opposite; you can't pass.

Game forcing, or merely forcing?

Partnerships play it one of two ways:

• Game forcing: the fourth suit promises enough for game and neither player may stop below it. Simpler, and the more common agreement.
• Forcing for one round: it promises invitational values, and responder's next bid decides. More precise, and it needs a clear scheme for how responder signs off.

Unless you have a regular partner who wants the other version, play it as game forcing.

With an invitational hand and no fit you usually have another bid available. With a game force and no fit you often don't, and those are the hands to use it on.

Fourth suit forcing or new minor forcing?

Responder's bid can look the same in both. The difference is what opener rebid.

• Opener rebid 1NT: that's new minor forcing. Opener has shown a balanced minimum and denied four cards in your major, and the question is whether they hold three.
• Opener bid a second suit: that's fourth suit forcing. Three suits are on the table, opener's shape is unbalanced, and the question is broader: stopper, support, or extra length.

You can play both. Once you've agreed to, opener's rebid tells you which one applies.

What it costs

You lose the natural bid of the fourth suit, which you rarely want. To want to play there you would need real length in a suit nobody else has bid, on a hand that could have bid it earlier and didn't.

There's a second cost. Bidding the fourth suit tells the defenders your side may be weak in it, which helps them choose a lead.

On hands that end in 3NT with a single stopper in that suit, the opening leader knows where to attack. It's still cheaper than guessing the contract.

Four things to remember

1. Three suits bid by your side, fourth suit bid by you: artificial and forcing.
2. Opener answers stopper first, then major support, then shape.
3. Opener doesn't raise it. Responder hasn't promised that suit.
4. After a 1NT rebid it is new minor forcing instead. Check what opener rebid.