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
Principle of fast arrival to game leave less room for slam investigation, they imply an absence of slam values and therefore discourage more bidding. In addition, on weaker (or limited) hands fast arrival has a pre-emptive effect on the opposition and minimizes the information they might otherwise exchange. Stated conversely as the principle of slow arrival, the approach leaves more bidding space for stronger hands to explore for slam or choose the optimum game contract. Principle of fast arrival In the game of contract bridge, the principle of fast arrival (also known as the principle of slow arrival) is a bidding treatment widely used