Stayman Convention - Rationale

Rationale

A game contract bid and made in a major suit (i.e. 4♥ or 4 ♠) scores better than a game contract bid and made in a minor suit (i.e. 5♣ or 5 ♦) or in notrump (i.e. 3NT). Also, the success rate for a game contract in a major suit when a partnership has a combined holding of 26 points and eight cards in the major is about 80%, whereas a game contract in 3NT with 26 high card points (HCP) has a success rate of only 60%, or 50% with 25 HCP; the success rate for a minor suit game contract when holding 26 points is about 30%.

Accordingly, partnership priority is to find an eight card or better major suit fit when jointly holding sufficient values for a game contract.