Bidding Conventions >

Fourth Suit Forcing


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:

Opener
1
2
 Responder
1
2

Opener
1
1
 Responder
1
2

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:

  1. Showing 3-card support for partner's major
  2. Rebidding a suit to show extra length
  3. Bidding no-trumps with a stopper in the fourth suit
  4. 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.

OpenerResponder
JT3SKQT52
HKQT54A2
DAJ32
CKJ52A87

Opener    
1
2
2 (2)
Responder    
1
2 (1)
4 (3)

  1. Fourth Suit Forcing.
  2. Opener shows 3-card support and minimum strength. Note that he could bid 3 with 15-17 points.
  3. 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.

OpenerResponder
KQT7S65
HJAQT98
DKJT985A64
CA2JT5

Opener    
1
1
2 (2)
3NT (4)
Responder    
1
2 (1)
2NT (3)
Pass

  1. Fourth Suit Forcing.
  2. Opener shows his 6-card diamond suit. Note that with a stronger hand (15+ points), he could bid 3 instead.
  3. Responder invites game with his balanced hand and club stopper.
  4. 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.

OpenerResponder
7SKQ942
HAJT9463
DA95K63
CKQJ3AT2

Opener    
1
2
2NT (2)

Responder    
1
2 (1)
Pass

  1. Fourth Suit Forcing.
  2. 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.

OpenerResponder
9SAQ542
HAT84KJ9
DA975K43
CKQ6387

Opener    
1
2
3 (2)
Pass
Responder    
1
2 (1)
3NT (3)

  1. Fourth Suit Forcing.
  2. 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.
  3. 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):

    Opener
    1
    1
    		 Responder
    1
    1

    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:

    Opener
    1
    2
    		 Responder
    1
    3

    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:

    Opener
    1
    2
    		 Responder
    1
    3

    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:

    Opener
    1
    2
    		 Responder
    2
    2

    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