Transfer Stayman - 2
Most bridge players agree that it is usually a good idea that the player who opens 1NT should also be the declarer, with the opening lead coming up to the stronger hand. That's part of reason we have both Stayman and Transfer bids.
But consider the problem faced by Precision players... After an opening bid of 1 and a response of 1NT, the weaker hand will be the declarer if there is a 4-4 major suit fit.
We have a solution for that... It's called Transfer Stayman.
The 2 call by the opener is a Stayman bid, but responder uses Transfer calls to describe her hand:
A couple of example hands with comments:
Responder does not have a 4-car major, so she bids 2, which denies a major suit.
With both majors, responder bids 2NT, which allows the opener to choose the major.
With only one 4-card major, responder transfers by bidding the suit under the major. With this hand, she bids 2, showing a 4-card heart suit and also denying a 4-card spade suit.
There is an adjunct to Transfer Stayman which we call Point-Count Stayman - this bid is only used after going through Transfer Stayman, as described above.
Point-Count Stayman - 3
After a Transfer Stayman inquiry, and the responses to it, the opener can ask another question by using 3 as a second question: "Partner, Now I know about majors, but how many points do you have?"