When can a player double an opponent’s bid in contract bridge?
Card editor of the London Field W.H. Whitfeld published this bridge problem in 1885. South is declarer and has the lead with hearts as trump. With a sophisticated finesse, South can win every trick. South begins by leading the ace of diamonds, which, depending on what the opponents discard, opens a possible finesse of North's jack of diamonds. Next, South passes the lead to North with a spade that North trumps. North then leads the last heart, and South discards the 10 of clubs. With the lead of the last trump and then the ace of clubs, the defenders are presented with an insurmountable dilemma. East must hold two diamonds or South takes the last two tricks in the suit by discarding a spade. However, in order to hold on to two diamonds, East must discard the jack of spades, which in turn would force West to hold the queen of spades. Since West also needs the queen of diamonds and the jack of clubs to avoid losing a trick, a discard from any of the three suits will allow South to win all of the remaining tricks by an appropriate discard.
In the game of contract bridge, a player may double the last preceding bid if it was made by an opponent and has not previously been doubled.1
Doubling is a strategic call made during the auction that serves different purposes depending on the intent:
- Penalty Double: This is used to increase the potential score for the defenders if they succeed in defeating the opponents' contract. When a contract is doubled, the points for tricks scored below the line are doubled, and the penalties for failing to fulfill the contract (undertricks) are significantly increased.23
- Takeout Double: This is used to convey information to one's partner, essentially requesting that they make a bid.4
A bid may be overcalled by another player regardless of whether it has been doubled or redoubled.1