Жакоби трансфері: көпірдегі келісімдер мен стратегиялар

The Jacoby transfer, or simply transfers, in the card game contract bridge, is a convention in most bridge bidding systems initiated by responder following partner's notrump opening bid that forces opener to rebid in the just above that bid by responder. For example, a response in diamonds forces a rebid in hearts and a response in hearts forces a rebid in spades. Transfers are used to show a long suit, usually a major, and to ensure that opener the hand if the final contract is in the suit transferred to, preventing the opponents from seeing the cards of the stronger hand. The use of the 2 and 2 (and often 2) responses to an opening 1NT bid as transfers is one of the most widely employed conventions in the game. Less commonly, partnerships may agree to use transfer style bids in a variety of other situations.

First described in a series of articles by Olle Willner of Sweden in Bridge Tidningen in the early 1950s, transfers were popularized for English speakers in 1956 in The Bridge World article by Oswald Jacoby and have gained widespread international acceptance by duplicate and rubber bridge players alike. In the article, Jacoby gave his name to the convention as the Jacoby Transfer Bid (JTB) stating that it was an adaptation of a bid then known variously as either the 'Texas Convention' or the 'Carter Transfer' (now known as the Texas transfer). The initial purpose of the convention was to make the notrump opener the declarer in a suit contract when his partner held a relatively weak hand with a long suit; this would make the opening lead come up to the stronger hand and such a situation is advantageous should declarer possess one or more or tenuously guarded honors. In addition, the exchange of information by the transfer bid and subsequent rebids by responder and notrump opener "is designed to help partnerships reach the right contract", i. e. their optimum contract. In the 1990s further developments of the transfer procedures enabled them to be used to even greater effect. The use of "bouncing" and "breaking" rebids by opener offered partnerships the opportunity to find safe game and slam contracts with fewer high card points than with traditional methods.

Although part of the early writings on transfers in the 1950s, "bouncing" and "breaking" have only become widespread in the UK since the 1990s. As promulgated by Paul Mendelson, they are:
Bouncing (also known as bypassing). Following the standard initiation of a transfer sequence (e. g. 1NT 2 ? ). Opener rebids 3 with a maximum point count (14 with Acol) and 4 card support for hearts. With all other hands, opener rebids 2. Breaking. Following the same initial sequence of 1NT 2 ? :
Opener rebids three of an unexpected suit (3) to show maximum points (14 with Acol) and a poor doubleton (xx) in the bid suit (e. g. diamonds)
With these two devices (bouncing and breaking) it is possible to discover, at very little risk, games that would otherwise be missed.

Transfers work well following other notrump bids. A common usage follows an opening bid of 2NT where a weak take out into three of a major becomes a possibility whereas with traditional methods such a bid would be forcing.

Standard bidding in most systems is that all responses following a natural suit overcall are themselves natural bids ("double" may be used for take out). An alternative is that such responses, including "double", act as transfers. For example, following a 1NT opening and a 2 overcall:
double transfer to hearts
2 transfer to spades
2 transfer to clubs