Negative double

The negative double (sometimes called the Sputnik double) is a form of takeout double in bridge. It is made by the responder after his right-hand opponent overcalls on the first round of bidding, and is used to show both support for the unbid suits as well as some values. It is treated as forcing, but not unconditionally so. In practice, the negative double is sometimes used as a sort of catch-all, made when no other call properly describes responder's hand. Therefore, a partnership might even treat the negative double as a wide ranging call that merely shows some values.

Using the modern negative double convention, it is understood that a double over an initial overcall is conventional, and not for penalties (but see Playing for penalties). For example, using this convention, the following doubles would be regarded as negative, not for penalty:

In understandings regarding negative doubles, the emphasis is on major suit lengths. This is largely due to the special value that tournament play, especially the pairs game, places on major suits. Since the mid-1980s, the negative double has been used mainly to stand in for a bid in an unbid major suit.

Most partnerships using the negative double agree that it applies only through a particular level of overcall. For example, they may agree that the double of an overcall through 3♠ is negative, and that beyond 3♠ a double is for penalties.

At rubber bridge many players are reluctant to give up the penalty double of an overcall, and so do not use the double as conventional.

The term negative double was initially employed to distinguish it from the penalty, or business, or positive double, and signified a double over an opponent's opening bid whose meaning was a request for partner to bid his best suit. Around 1930, the term informatory double replaced negative double, and that term later gave way to takeout double as it is used at present; the original term negative double fell into disuse.

In 1957, Alvin Roth in his partnership with Tobias Stone appropriated the abandoned term negative double to denote a conventional double by responder over an overcall and gave it its current meaning. The bid was also briefly known as Sputnik, because it was as new as the satellite of that name that the Soviet Union had recently launched. The term is still used sometimes in Europe.

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