Source: Morehead on Bidding.
Wikipedia: Albert Hodges Morehead, Jr. (August 7, 1909 – October 5, 1966) was a writer for The New York Times, a bridge player, a lexicographer, He wrote The New York Times bridge column for more than 25 years.
“Any experienced bridge player knows that one cannot win without doubling the opponents when they overbid. Against this indisputable fact there is the contrary fact that a double often gives the declarer information that permits him to save a trick or even to make a contract he could not have made if he had not been doubled.”
The following deal proved to be a lesson to the player who doubled unwisely.
Dealer North. Both Vul
A Q 4
6 4
A K Q 10 6
7 4 2
K 10 9 3
A 7 2
7 3
K Q 9 8
2
10 9 8 5 3
8 5 4
10 6 5 3
J 8 7 6 5
K Q J
J 9 2
A J
West
North
East
South
1
Pass
1
Pass
2
Pass
4
Dbl
Pass
Pass
Pass
West opened the K and South took it with his ace. South saw one club trick to lose, and a second trick to lose to the ace of hearts, and probable losing trick in spades.
If West had not doubled, South’s play would have been quite simple. He might have made the percentage play of the space ace, surrendering his best chance of getting an overtrick if a spade finesse won but guarding against a singleton king of spade in the East hand; or he might have made the usual play of leading a small spade from his hand and finessing dummy’s queen on the first round.
Whichever oh these two plays South selected, he would have gone down. West would have been left with two trump tricks, plus the heart ace and club queen. But South was forewarned by West’s double and figured West for a four card trump holding, at least K 10 3 2 and perhaps (as was the actual case) K 10 9 x.
In either case, South had advantage by leading the J from his hand on the first trump trick. South did lead the J and West could not play so as to get more than one spade trick.
West covered the J with the king and dummy’s ace won the trick. South reentered his hand leading the6 and taking it with the9 in his hand. Them South led the8 and West tried to save himself by playing the3, but South played the4 from dummy and the eight won the trick. Dummy´s queen drew another round of trumps, leaving West with only one trump trick, the ten.
If West had covered the8 he still would have had only one trump trick, for dummy´s queen would have taken the trick, another spade lead would have forced out West’s ten, and South would have had the high spades to draw West’s last trump, which was the lowly three.
West’s double cost his side 890 points, the difference between the 790 South scored and the 100 E-W would have scored if West had kept quiet.