Quest transfers is a convention. This convention is alertable. Its prerequisite is Stayman.
Quest transfers are a nonstandard conventional rebid in 1NT auctions. After 1NT--2♣--2♦, the opener has denied a four-card major, but likely has three-card majors. Thus, with 5-4 (sometimes 6-4) majors, after giving opener his choice of majors with Stayman, it is useful to be able to transfer to a major of the responder's choice. This is very similar to Smolen transfers, but more useful since Smolen only applies to game-forcing auctions, while Quest transfers may be used with as little as invitational strength, since it is possible to sign off in 3 of the major with a Moyesian fit in the worst case.
Convention 
Edit
After 1NT--2♣--2♦, the following bids are defined
- 3♦ is a transfer to 3♥ with 5+ hearts, 4 spades, and at least 8 points.
- 3♥ is a transfer to 3♠ with 5+ spades, 4 hearts, and at least 8 points.
Opener's response Edit
In order for this convention to work with invitational hands, opener must bypass the transfer with maximum strength. Responder will pass to stay below game, with only 8 points.
- With 15-16 points (minimum opening), accept the transfer by bidding 3♥/♠.
- With 17 points (maximum) and a doubleton in partner's major, bypass the transfer by bidding 3NT.
- Partner will retransfer by bidding 4♦/♥ with a 6-card suit.
- With 17 points, 3 cards in partner's major, and an outside ace, bypass the transfer by cue-bidding the outside ace.
- Partner will either cue-bid aces or else retransfer by bidding 4♦/♥ if possible.
- With 17 points and 3 cards in partner's major, and no outside ace, bypass the transfer by bidding 4 of the major.
