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 Official Encyclopedia of Bridge The Official Encyclopedia of Bridge The Official Encyclopedia of Bridge (OEB) presents comprehensive information on the card game contract bridge with limited information on related games and on playing cards. It is "official" in reference to the American Contract Bridge League (ACBL) which authorized its production and whose staff prepared and/or supervised its various editions. The first edition of the "Encyclopedia" was published in 1964 with Richard Frey as Editor-in-Chief; it was the only one with an edition revised for an overseas market ("The Bridge Players' Encyclopedia", 1967). The seventh and latest edition was published in 2011 following intermediate editions