In competition, one makes two statements with a bid. The first is that one possibly wants to declare the contract with his suit as trump, and the second is that if he ends up as a defender, he wants partner to lead his suit.
If both of these declarations are true, an overcall can be made. Furthermore, an overcall does something subtle that every bridge player should recognize.
If one’s partner makes an overcall, one must make an immediate assessment. With two or less cards in partner’s suit, one tries to be a defender.
With three or more cards in partner’s suit, one tries to be dummy if the level is not too high. The Law of Total Tricks and an honour assessment can be used as guidelines.
Honour assessment is as follows. Wasted honours that are unlikely to promote an honour in partner’s hand or honours that are in the pocket (finesseable) tell one to defend and not to push the opponents too eagerly.
The Bidding: East, with 13 HCP’s, opens One Heart. South makes a One Spade overcall, and West raises partner to Two Hearts. North, by not passing, makes a cardinal sin by falling into a double misfit at the three-level. Double fits increase the value of the hands, and a double misfit torpedoes the contract. East doubles to take advantage of the situation. Doubles after a fit has been found are for penalty.
South, makes a second cardinal sin by running to three Spades which also gets doubled.
The Result: Three Spades is down two, and three Clubs is down three. So, by running, South saved a trick, but it is generally accepted to let partner play the doubled contract unless he redoubles.
An SOS redouble asks partner to run to a different suit. This type of redouble only applies to the person being doubled. However, if the partner of the person being doubled redoubles, it says “Partner we are making this.” Far from the case here.