Safety play in contract bridge is a generic name for plays in which declarer maximizes the chances for fulfilling the contract (or achieving a certain score) by ignoring a chance for a higher score. Declarer uses safety plays to cope with potentially unfavorable layouts of the opponent's cards. In so doing, declarer attempts to ensure the contract even in worst-case scenarios, by giving up the possibility of overtricks.
Safety plays adapt declarer's strategy to the scoring system. In IMP-scoring tournaments and rubber bridge, the primary scoring reward comes from fulfilling the contract and overtricks are of little marginal value. Therefore, safety plays are an important part of declarer technique at quantitative scoring.
In matchpoint games, which use comparative scoring, overtricks are very important. Therefore, although safety plays have a certain role at matchpoints, they are normally avoided if the odds for making the contract are good and overtricks are likely.
The term safety play is difficult to define crisply. The Bridge World glossary defines safety play as "the surest line to make the contract, disregarding extra tricks that might be made in some other way." Marshall Miles has defined it as "playing in such a way as to lose a trick with average breaks in order to avoid losing additional tricks with bad breaks."
Conflating discussions from various sources yields the following points, each descriptive of safety play characteristics:
Safety plays have a role at both comparative scoring and quantitative scoring, although they are used more often at quantitative scoring because they tend to give up on overtricks.
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