Jacoby transfers are the simplest of the transfer bids. They apply after any natural 1NT, 2NT, or 3NT opening. In short, the responder bids the lowest level of ♦ or ♥ as a request for the opener to bid ♥ or ♠, respectively. Jacoby transfers may be done with any strength hand and always require a 5-card suit. Since a natural notrump opening has at worst a single doubleton, there is a chance (roughly 25%) of a 7-card fit, but much more likely is an 8-card or better fit.
The primary reason for using transfers is to keep the stronger hand hidden. In particular, if the opener holds tenaces such as A-Q or K-J, there is a big disadvantage to having them on board which may cost several tricks.
Jacoby transfers are also called major suit transfers, since the targets are major suits, and red suit transfers, since a red suit bid is transfer.
After 1NT Edit
|6-card major||raise to 3||raise to 4|
- With less than 8 points and five hearts, bid 2♦. With five spades, bid 2♥. In either case, pass opener's rebid, since game is likely impossible.
- With 8-9 points and a five-card major, bid the transfer and then rebid 2NT. Opener will select between 2NT, 3 of the major, 3NT, or 4 of the major.
- With 8-9 points and a six-card major, bid the transfer and then rebid the major at the three level to invite game.
- With 10-15 points and a five-card major, bid the transfer and then rebid 3NT as a game choice.
- With 10-15 points and a six-card major (with no slam hopes), bid 4 of the major
- With 15+ points and at least a five-card major, bid the transfer and then do something else.
- The cases with at least 5-4 in the majors (particular with 5-5 in the majors) are subject to partnership agreement as treatments vary a lot. Stayman or Jacoby transfer may be used in different situations.
After 2NT Edit
Most of the above applications apply equally well after a 2NT opening.
- With less than 4 points and five hearts, bid 3♦. With five spades, bid 3♥. In either case, pass opener's rebid, since game is likely impossible.
- With 4-10 points and a six-card major, bid the transfer and then rebid the major at the four level to sign off in game.
- With 4-10 points and a five-card major, bid the transfer and then rebid 3NT as a game choice
- With 11+ points and at least a five-card major, bid the transfer and then do something else to indicate slam interest.
After a Natural 3NT Edit
While natural 3NT openings are not recommended, Jacoby transfers still apply after them. Since they are so uncommon, it is not well established whether this requires a 5- or a 6-card suit. Note that Texas transfers would be equivalent in this case.
Bypassing a Transfer Edit
There are several schools of thought regarding the opener's options when responding to a Jacoby transfer. On the one hand, because responder may have absolutely nothing, some say the opener has no choice and must always respond at the lowest level.
On the other hand, the Law of total tricks suggests that if the opener is long in the transferred suit (4+ cards) then there is at least a 9-card fit and therefore bidding at the 3-level is safe anyway. Thus, with 4+ trump and a maximum (17 point) opening, opener may bypass the transfer by jumping a level.
Extended bypasses Edit
It is possible to further extend the idea of bypassing a Jacoby transfer. Since the intervening bids between 2 and 3 of the major are all unused, they can be made into splinter bids or control-showing cue-bids. In these cases, the same conditions (4+ trump and maximum opening) still apply. This may open up the possibility of a slam which was otherwise undiscovered. On the other hand, it gives the opponents more information about what was originally intended to be the hidden hand. At this point, responder may request a retransfer by making the bid directly below the 3-level major. Alternately, the responder may opt to become declarer.
Some partnerships play that a transfer can be denied with no fit by bidding the cheapest notrump. Responder may still retransfer. Many prefer not to use this treatment because if the responder had nothing, the choice is between 2NT or possibly 3 of the major with a 7-card fit, neither of which is particularly good. Also, since the responder typically clarifies the transfer with the next rebid, this treatment only serves to give more information about the hidden hand.