Grand slam force Grand slam force The Grand Slam Force is a bidding convention in contract bridge that was developed by Ely Culbertson in 1936. It is intended to be used in cases where the combined hands of a partnership are so strong that a slam (winning at least 12 tricks) is a near-certainty and a grand slam (winning all 13 tricks) is a possibility. It allows one partner to gain information on the quality of trumps in the other partner's hand. When this convention is in force, a bid of 5NT (five notrump), when it does not conflict with other conventions used
Contract bridge doubled or quadrupled if the contract is respectively doubled or redoubled. In rubber bridge, a partnership wins one game once it has accumulated 100 contract points; excess contract points do not carry over to the next game. A partnership that wins two games wins the rubber, receiving a bonus of 500 points if the opponents have won a game, and 700 points if they have not. Overtricks score the same number of points per odd trick, although their doubled and redoubled values differ. Bonuses vary between the two bridge variations both in score and in type (for example, rubber bridge