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
The Bridge World the magazine has periodically polled experts on various bidding treatments and conventions in order to develop a unified system of bidding known as Bridge World Standard. There have been five versions of the system with the latest revision being the 2017 edition. Bridge World Standard has evolved with the practices of North American experts and, similar to the Standard American Yellow Card system promulgated by the American Contract Bridge League, is offered as a system "for use by impromptu or casual partnerships, and as a basis for discussion by those who wish to formulate their own system." The Bridge World