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
Law of total tricks contract. It is of most value in competitive bidding situations where the HCP are divided roughly equally between the partnerships. LoTT is said to be most accurate when the HCP are fairly evenly divided between the two sides and the bidding is competitive. Experts apply adjustment factors to improve accuracy. Payne and Amsbury's "Bridge: TNT and Competitive Bidding" (1981) may have been the first major book on the topic. In the introduction, the authors acknowledge Jean-René Vernes as the first writer to investigate TNT (Total Number of Tricks) Theory. Page 19 includes a key table that may not have been