Fourth Suit Forcing occurs when a partnership bids all four suits in the first two bidding rounds. The fourth suit bid is artificial with game-invitational values (10+ points). Although some partnerships play it as game-forcing, this description will explain the more flexible "one-round force" approach.
Example auctions:
In each auction, the last bid suit is Fourth Suit Forcing, showing game-invitational values or better. It does not necessarily show or deny an actual suit.
Opener's Rebids
Opener's rebids are natural. However, the priorities are:
- Showing 3-card support for partner's major
- Rebidding a suit to show extra length
- Bidding no-trumps with a stopper in the fourth suit
- Raising the fourth suit with 4 cards in that suit (rare)
If playing Fourth Suit Forcing as a one-round-force (not game-forcing), then opener must make jump bids to show extra values and commit the partnership to game.
1. Showing 3-card support for partner's major
Opener should strive to show 3-card support if partner's FIRST suit was hearts or spades.
| | | Opener | | | Responder |
| | JT3 | | KQ952 | |
| | KQT54 | | A2 | |
| | A | | J32 | |
| | KJ52 | | A87 | |
|
|
Opener
1
2
2 (2)
|
|
Responder
1
2 (1)
4 (3)
|
- Fourth Suit Forcing.
- Opener shows 3-card support and minimum strength. Note that he could bid 3
with 15-17 points.
- Responder jumps to game with 14 points.
2. Rebidding a suit to show extra length
Opener can rebid his first suit to show 6-4 shape, or he can rebid his second suit to show 5-5 or longer.
| | | Opener | | | Responder |
| | KQT7 | | 652 | |
| | J | | AKT98 | |
| | KQT985 | | 64 | |
| | K2 | | AT5 | |
|
|
Opener
1
1
2 (2)
3NT (4)
|
|
Responder
1
2 (1)
2NT (3)
Pass
|
- Fourth Suit Forcing.
- Opener shows his 6-card diamond suit. Note that with a stronger hand (15+ points), he could bid 3
instead.
- Responder invites game with his balanced hand and club stopper.
- Opener accepts the game invitation with 14 points.
3. Bidding no-trumps with a stopper in the fourth suit
Opener can rebid no-trumps if he lacks 3-card support for partner's major suit.
| | | Opener | | | Responder |
| | 7 | | KQ942 | |
| | AJT94 | | 63 | |
| | A95 | | K63 | |
| | KQJ3 | | AT2 | |
|
|
Opener
1
2
3NT (2)
|
|
Responder
1
2 (1)
Pass
|
- Fourth Suit Forcing.
- Opener jumps to 3NT with a diamond stopper and 15-17 points.
4. Raising the fourth suit with 4 cards in that suit
This occurs when opener holds a 3-suiter which is short in partner's first-bid suit.
| | | Opener | | | Responder |
| | 9 | | AQ542 | |
| | AT84 | | KJ9 | |
| | A975 | | K43 | |
| | KQ63 | | 87 | |
|
|
Opener
1
2
3 (2)
Pass
|
|
Responder
1
2 (1)
3NT (3)
|
- Fourth Suit Forcing.
- Opener shows a 4-4-4-1 or 5-4-4-0 pattern. Note that he could not have bid hearts at his second turn, because that would have been a reverse promising 17+ points.
- Responder knows that opener has a 3-suiter, but chooses to bid 3NT with a balanced minimum.
When Fourth Suit Forcing Is Off
Fourth Suit Forcing is OFF if any of these conditions apply:
- Responder is a passed hand.
- The opponents overcall or make a takeout double.
- The partnership bids all four suits at the 1-level (rare):
In this auction, responder's 1
bid is natural and forcing for one round. However, it is not Fourth Suit Forcing (i.e. artificial).
- Opener has made a reverse, showing 17+ points:
In this auction, opener's 2
bid was a reverse (forcing), because he bypassed 2
. Therefore, responder's 3
bid is natural.
- Responder makes a jump-shift in the fourth suit. This is a natural bid, not Fourth Suit Forcing:
Responder is showing a 2-suited hand (at least 5-4).
- Responder makes a 2-over-1 response at his first turn. His second bid (the fourth suit) is natural, not Fourth Suit Forcing:
Responder is showing a 2-suited hand with longer clubs.
When to Use Fourth Suit Forcing
Fourth Suit Forcing should only be used when responder does not have another attractive bid available, such as:
- Rebidding a 6-card suit
- Bidding no-trumps with a stopper in the fourth suit
- Making a delayed 3-card raise of partner's major suit opening bid
- Raising partner's second suit with 4+ card support