|
EHAA (''Every Hand An Adventure'') is a highly natural bidding system in contract bridge characterized by four-card majors, sound opening bids, undisciplined weak two-bids in all four suits and a mini notrump, usually of 10–12 high card points. ==Weak two-bids== An EHAA two-bid shows six to twelve high card points, and a five card or longer suit. There are no restrictions on suit quality (xxxxx and AKQJxxxx both qualify). EHAA bidders use a "get in quick, get out quick" style, which permits interference or an opening bid in nearly every auction, protected by fairly strict requirements on further bids by the partnership. EHAA two-bids are made in ''all four suits''; there is no forcing opening bid in EHAA. Responses to the EHAA two bid fall into three categories. All jump bids are forcing to game and slam invitational, because any hand which could force to game opposite a minimum EHAA two-bid must be interested in slam opposite a maximum. (However, a direct jump to game is a two-way bid, and opener is expected to pass.) A nonjump bid in a new suit is a ''nonforcing'' and ''nonconstructive'' attempt to improve the contract. Finally, 2NT or a raise of the opening bid shows 14 to 17 high card points, and is invitational to game; a raise shows three card support or better, and 2NT denies three card support. (If responder has an invitational hand without support, but cannot abide opener's possible pass of 2NT, he must guess whether to bid game or not.) After an EHAA two-bid, delicate game bidding is not possible; this is one of the disadvantages of the system. If responder holds 12 or 13 points, he cannot raise, though game might be possible if opener has a maximum. Lowering the point range for a raise could solve this difficulty, at the considerably greater expense of risk when opener has a bad minimum. Notice that responder cannot further the preempt, in accord with the "get in quick, get out quick" strategy of the EHAA two-bid. Responder can escape from opener's suit, however, by correcting to a new suit. This shows that responder has at least four cards more in his suit than he does in opener's suit. Opener can correct to a third suit or back to his original, with a similar meaning. Both partners must be aware that the combined assets of the partnership may be extremely weak, and should be ready to stop at the earliest opportunity. Neither partner may raise a suit bid by the other; the partnership is already known to be limited. Systemically, any hand meeting the requirements for an EHAA two-bid ''must'' be opened as such. EHAA two-bids are also used as overcalls, but of course are not obligatory. Considerations of safety and vulnerability must then come into play. If the opponents bid over the two-bid, responder need not have the ability to take out opener's bid to his own suit, and so all new suit bids in such a context become constructive and show values, though still nonforcing. If the opponents have shown opening bid values (either with a takeout double or because they opened the bidding), jump raises of 2 and 2 show game invitational hands stronger than a simple raise would. (Because a takeout double could be passed for penalties, however, it is still necessary for responder's new suit response to be nonconstructive after a double.) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「EHAA」の詳細全文を読む スポンサード リンク
|