Support (re)double

A support (re)double is used to show 3 cards in a major to look for a possible 5-3 fit.

A (re)double is support if

• the doubler has opened the bidding (or overcalled opponent's opening bid); and
• partner has responded with a major that promises only 4+ cards

The support (re)doubler promises 3-card support in partner's major.

Some examples of support double are as follows:

• 1C > 1H > (1S) > X promises 3 hearts
• 1C > 1S > (X) > XX promises 3 spades

A (re)double is still support if partner has used a negative double to show 4+ cards in a major instead of bid the suit, provided that a 5-3 fit is still possible. Some examples are as follows:

• 1C > (1D) > X > (1S) > X promises 3 hearts (responder may have 5-4 or 5-5 in majors)
• 1C > (1S) > X > (2D) > X promises 3 hearts (responder may have 5 hearts but are not strong enough to bid to 2-level)
• 1C > (1H) > X > (2D) > X is not support double since responder has denied 5 spades by using negative double instead of bidding 1S