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
Trick-taking game hold an auction for it. The most popular games of the 18th-century was tarot which experienced a great revival. During this time, many tarot games borrowed bidding over the stock (taroc-l'hombre). In the 20th century, Whist (now with bidding and the dummy hand) developed into Contract bridge, the last global trick-taking game. It is possible that the origin of the practice of counting tricks (in plain-trick games) was the counting of cards won in tricks. It was therefore a logical development to accord some cards a higher counting-value, and some cards no value at all, leading to point-trick games. Point-trick