The Grand Slam Force is a convention that uses an artificial 5NT bid to ask partner about the quality of his trumps, for the purpose of probing for a grand slam. After a trump fit has been found (or implied; 1:5NT would indicate a heart fit), any 5NT bid that does not conflict with other conventional meanings a pair has agreed on (i.e. a 5NT Blackwood rebid) asks partner to bid a small slam with less than two of the top three honor cards in his suit, and to bid a grand slam with two top honors.

The grand slam force is usually used when one player has one top trump honor and is certain all the other suits are completely stopped, but needs to find the other two top trump honors in partner's hand in order to count 13 tricks.

See also

  • 5NT Pick a Slam
    A conventional 5NT bid that asks partner to choose a small slam.

  • Baby Blackwood
    A conventional 3NT ace-asking bid after a major-suit fit is found.

  • Blackwood
    The original 4NT convention invented by Easley Blackwood to ask for aces.

  • Exclusion Blackwood
    A variation of Roman Key Card Blackwood that's used with a void.

  • Gerber
    The convention for asking for aces in no-trumps slam auctions.

  • Roman Blackwood
    The Italian variation of Blackwood upon which RKCB is based. The responses to 4NT include the rank and colors of the four aces.

  • Roman Key Card Blackwood
    A popular variation of Blackwood that asks for aces and the king of trumps.

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