We think that all long-term partnerships should play some form of ‘new minor forcing’. The primary reason is that this greatly facilitates bidding after the very frequent auctions that begin one of a minor – one of a major – one notrump. Playing any reasonable type of ‘new minor forcing’ allows the partnership to bid much more accurately. The primary benefits of new-minor-forcing are (1) avoiding ambiguity about responder’s strength and (2) keeping the auction as low as possible in game-invitational situations. Our preferred new-minor-forcing approach is “XYZ”; here is a discussion of the most basic form of “XYZ”. Advanced XYZ partnerships can and usually do have additional more sophisticated agreements.
The title “XYZ” refers to any auction that begins “one X”, pass, “one Y”, pass, “one Z”. The most frequent example is one minor – one major – one notrump, but partnerships who use XYZ typically also use this approach in each of the following additional auction types: One heart – one spade – one notrump; One minor – one heart – one spade; One club – one diamond – one heart; and One club – one diamond – one spade. After any of these “XYZ” starts to the auction, responder’s rebids of two clubs and two diamonds are both artificial and forcing.
Responder’s two club rebid forces opener to rebid two diamonds but is forcing for one round only. Now responder passes to sign off in diamonds and bids something else to show some sort of invitational hand (most often, rebidding two notrump to invite in notrump or rebidding two of responder’s major to invite with a five or six card suit).
Responder’s two diamond rebid is forcing to game. Opener’s first duty is to show three-card support for responder’s major suit. In most partnerships, opener’s second duty is to show four cards in the other major. Typically opener rebids two notrump with any other hand type; responder’s rebid then clarifies the nature of responder’s game force (most often, responder rebids in notrump to show a game-forcing balanced hand, or rebids responder’s major to show a game-forcing hand with six-plus cards in the major suit).
To sign off in clubs after an “XYZ” start, responder rebids three clubs.
In general, if responder does not rebid two diamonds, responder denies game-forcing values. In general, if responder does not rebid two clubs, responder denies game-invitational values. Specifically, if responder rebids responder’s major suit, that is to play and denies any interest in game.