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
Optimum contract and par contract and that neither side could improve by further bidding. It will either be equal to the optimum contract of one side or it will exceed the optimum contract of both sides. If the latter, it is only considered par if the doubled penalty is less than the value of the opposing optimum contract. The par result is that score that arises from the par contract and on which neither side could reasonably improve by changing their line of play. Game theoreticians would refer to such a par result as a Nash equilibrium. The term par score originated in the game