Fourth Suit Forcing

From Hardy. Fourth suit is forcing and shows at least invitation to game. Responder jumps or bids game with extra values.

We do not play 1C 1D 1H 1S as being fourth suit forcing.

Responder's priorities:

  1. Showing 3 card support for partner's major
  2. Showing 4 card support for the fourth suit. Is this forcing without a jump? The fourth suit can be supported with 3 and no stopper, if responder has previously denied having 4.
  3. Showing a stopper in the 4th suit
  4. Making a descriptive bid
  5. With nothing to bid, rebid his cheaper (!) suit. If he really has a 6-5 distribution, he has to bid his second suit again.

In this treatment, 4th suit forcing is a lot like New Minor Forcing. We sometimes play fourth-suit forcing on the three level, to ask for a stopper in the unbid suit. Then we don't pass up 3NT just to support the 4th suit.