（接1楼原文的英文资料） 标 题: John Hoffman的Good-Bad 2NT Good/Bad 2NT By John Hoffman We thank John Hoffman (hoffman) for allowing us to publish this article. He has been playing online for many years and was awarded the Angelfish two years ago for his work teaching others and his ethics and etiquette at the table. You can find more of his articles at his website: members.home.net/ leilas/hoffman/bridge.htm SUMMARY This is a description of the Good/Bad 2NT convention as played in my partnership with Leila Sink. This convention uses 2NT in competitive situations as an artificial bid to show a hand that is weaker than bidding directly at the three level. The intended audience for this article is expert players in steady partnerships. INTRODUCTION Consider this contested auction: 1D-1S-Dbl-2S ? You hold one of these hands that should compete respectively to 3H, 3D, 3C: 84 A742 AK53 Q97 8 K7 AKT9543 Q97 84 4 AKT53 AQ974 Or you hold one of these hands that should invite to game: 8 AJ42 AK532 Q97 8 A7 AKT9543 K97 84 4 AKQ53 AQJ74 As you can see, it is hard to make affordable natural bids that clearly distinguish between competitive and invitational values in this situation. Now try another one: 1H-1S-2C-2S ? Suppose the bidder would like to bid a suit at the 3 level. This time, the auction is already game invitational for the bidder’s side. So the issue is how to show whether the hand is competitive or game-forcing. A good solution in these sequences is to use 2NT as an artificial bid that shows the weaker of the two hand types in the given situation. This allows direct bids at the 3 level to be natural and the stronger of the two hand types. WHEN IS IT GOOD/BAD 2NT? The biggest problem in using Good/Bad 2NT is knowing for sure whether it applies to each possible situation. Expert practice varies widely. The following 3 requirements must all be met, otherwise it is not Good-Bad 2NT: Both sides have bid. There have been 3 or more non-passes, and the most recent bid is 2 of a suit by right hand opponent (RHO). Special case: if RHO made a weak jump overcall, then 2NT is Good-Bad. You wish to bid a specific suit that is lower in rank or (rarely) equal to that of RHO’s suit. The partner of the Good/Bad 2NT bidder usually bids 3C. Partner should make some other bid to show suit preference, an unexpectedly long strong suit or enough extra strength to force the bidding higher. ALERT EXPLANATIONS 2NT is artificial and shows a hand that will compete in some suit at the 3 level that is of a rank lower than or equal to RHO’s 2 level bid. If neither partner has invited or forced to game: 3 of a suit is natural and invitational (as opposed to competitive). If either partner has invited but we are not yet forced to game: 3 of a suit is natural and game forcing (as opposed to competitive). If the context of the auction shows which suit(s) the 2NT bidder is probably competing in, that should be in the explanation. Further information (if requested): Responder makes the best bid for the situation, with a default to 3C. COSTS AND BENEFITS There is no free lunch in bridge. Good/Bad 2NT replaces 2NT as a natural bid (or as a scramble or other conventional call). Fanatics will assure you that no one wants to play a contract of 2NT, but some of the time you definitely will regret the loss of this descriptive bid. Our experience is that Good/Bad 2NT is a clear winner in frequency and size of benefits. Good/Bad 2NT requires some discussion, practice, and memorization. Initially there tend to be many failures to alert and instances of giving misinformation. A good approach is to play several sessions without using it. Try to identify in the post mortems each situation in which it would have applied, both for our side and the opponents. Good/Bad 2NT provides an actively ethical solution to a class of bidding problems that traditionally have been handled (unintentionally, of course) by timing and body language. The convention occurs fairly often, typically once to several times per session. Furthermore, it is fun to use. It provides a basis for fine-tuning auctions, usually without other changes in partnership agreements. Good/Bad 2NT is a good tool for both sides, regardless of which side opened the auction and what opening bid was made. It is equally useful at any vulnerability and form of scoring. The Good/Bad 2NT convention is applicable to virtually all bidding systems in which the 2NT bid has not already been assigned some other special conventional meaning. Miscellaneous notes The 2NT bidder has the option to compete further after having limited the hand. This might occur with extra length, especially in a minor, or after partner has shown a preference that improves the hand. In a close decision, it often is right to make the direct suit bid to show the suit pattern of the hand. This goes well with a style of aggressively inviting. It also anticipates a tendency of opponents to frequently bid directly over the competing 2NT call, preventing the 2NT bidder from clarifying the hand. On the flip side, it can be right to compete with a very marginal hand and hope that LHO will be enticed to take the immediate push. Good/Bad 2NT can be used to distinguish between an average hand and a perfect maximum within an already limited range. For instance, responder might use it in this situation: 1D-pass-1NT-pass 2D-2S-? We play that the Good/Bad 2NT bid is non-forcing (although rarely passed) but some play it as forcing. The basic rule regarding the number of non-passes might need to be modified when a Forcing Pass system is in use by either side. When is it not a Good/Bad 2NT situation? Here are some cases where Good/Bad 2NT does not apply in our methods: 1. Only one side has made a non-pass. 2. There have been fewer than 3 non-passes in a competitive auction. In these examples, we play 2NT as a natural game try: 1S - 2D- 2NT 1H - 1S - 2NT 3. RHO\'s bid is not a suit. 1S - 2H - dbl - ? 4. They use a convention at the two level against which we employ some other predetermined defense. 5. The other side starts the auction with a strong artificial bid showing at least 16 hcp. Acknowledgements Todd Walker (Milpitas, CA) developed most of the details of this approach. The Good-Bad 2NT convention is explained (with a somewhat different set of methods) by Marty Bergen in his book Better Bidding With Bergen Volume Two. Marc Smith wrote an excellent series (again with different methods) in the OKbridge Spectator. 标 题: Re: John Hoffman的Good-Bad 2NT Good/Bad 2NT From: John Hoffman (hoffman@hal.COM) The Good-Bad 2NT convention is described by Marty Bergen (Better Bidding Vol ume 2). Mike Lawrence has a similar convention with a different name in his most recent book on Competitive Bidding. As used in my partnerships, the convention is used by either partner in comp etitive auctions to distinguish between 1. competitive and invitational hands (most frequent) 2. invitational and game-forcing hands (less frequent) Going directly to the 3 level instead of using Good-Bad 2N shows invitationa l values in case 1, and shows game-forcing values in case 2. The Good-Bad 2N bid is artificial and shows a hand with the lower of the 2 p ossible value ranges in each case. It is nominally forcing, and nominally re lays to 3C (allowing the NT bidder to pass or select a signoff location). In some cases, partner will correctly refuse to relay to 3C. Our rules for when it applies differ somewhat from Bergen\'s. We play that it is on under these conditions: 1. RHO\'s most recent call is a suit bid at the 2 level 2. our side has made at least one bid which is not a pass 3. the bid is obviously needed to distinguish the value ranges. A few typical examples of Good-Bad 2N (opponent\'s bids in parentheses)... 1H - (Pass) - 1N - (2S) - ?? 3H = invitational values, natural 3C or 3D = invitational values, natural 2N = Good-Bad 2N: competitive values, with suits unspecified (1S) - DBL - (2S) - ?? 3C or 3D or 3H = invitational values 2N = Good-Bad 2N (1C) - DBL - (1S) - Pass; (2S) - ?? 3C or 3D or 3H = invitational values (opposite a pass: this should be a very strong single-suited hand) 2N = good-bad 2N (strong single-suited hand willing to compete) 1H - (1S) - 2D - (2S) - ?? 3C or 3D or 3H = game-forcing 2N = Good-Bad 2N, only invitational opposite a minimum 2D bid ============================================================================ hbear收集到的资料: 标 题: Clarifying 2NT bids in competition zz from:http://rsc.anu.edu.au/~mabraham/systems/Std_2NTinComp.doc Clarifying 2NT bids in competition Mark Abraham (with acknowledgements to Marc Smith, Andrew Robson and Oliver Segal) Theory: That when we have already shown a suit or suit(s) and the opponents have entered the auction at the one- or two-level (other than by doubling, w hich we largely ignore) then we will not want to use 2NT in a natural sense. Instead 2NT is used to show a hand capable of three-level action in the cont ext of the auction and vulnerability. Direct three-level action also shows a hand capable of three-level action. However there are hands that are shapel y and are merely contesting a part-score, and other hands which are interest ed in playing in game that are in danger of being preempted out by the oppon ents\' actions. We can utilize the 2NT-or-3-level choices to differentiate th ese hand types. 2NT will sometimes be the stronger action, and sometimes the weaker action, depending on the logic of the auction. The criterion that determines this is the action(s) previously taken by the bidder\'s partner. 1. If partner has shown weakness, then there may be real danger that the opp onents own this auction. Bidding 2NT with the weaker style of hand may allow the opponents an easy \"action\" double leading to a penalty of our three-lev el contract. Additionally we would like to act preemptively when we suspect they own the hand. Hence, when partner has shown weakness, then direct three -level action is weaker than going via the \"Good\" 2NT. 2. If partner has shown values, then we may be interested in bidding a game constructively when the bidder holds the strong hand. We are also in grave d anger of being preempted further, so that we need to take direct descriptive action with our stronger hands. We do not mind further action by the oppone nts (at the three-level) when we only had a hand contesting the part-score. Hence, when partner has shown values, then direct three-level action is stro nger than going via the \"Bad\" 2NT. It remains to define what actions by partner show weakness, and which show v alues. We choose that partner shows weakness only by passing, or by making a n overcall at the one-level. All other actions show values. These choices se em to work. A case might be made for adding Weak Jump Shifts by responder (1C-P-2H with few HCP and 6+H) to the weakness definitions, but not Negative Free Bids by responder. The 2NT bids require partner to take correctable actions. When partner would have passed a natural 3C bid that had the strength that has now been announ ced by the 2NT bid, then partner must bid 3C, which the 2NT bidder will now pass. If partner would have taken some action over a 3C bid, then he is obli ged to either make the lowest bid he would have passed, or take some other s trong action. Doubles in such auctions are takeout unless otherwise defined (e.g. support doubles). An example is in order: Here your negative double shows values, so partner\'s 2NT will be a weaker ha nd. Pard RHO You LHO 1H 1S X 2S 2NT Pass ? ¨ If you held Qxx xx Jxxx Kxxx then you would have passed if partner bid a non-encouraging 3C, so you must bid 3C. If partner then bids 3D then you wil l also pass, since partner\'s strength was expressed by 2NT. Likewise you wil l pass his correction to 3H, which shows an opening hand with a likely seven -card suit. ¨ If you held xx AQ xxxx KJTxx then you would again bid 3C, since partner\'s 2NT has already warned you that he is only interested in part-score. You wo uld also pass any correction by him. (It is true partner might hold x KJxxxx x AQJ xx but you will have another chance after his 3H bid; you certainly do n\'t want to force the auction now, and be in 4H or 5C when he has xx Kxxxx K x AQxx) ¨ If you held xx Kx AJxx KQJxx then you cannot bid 3C. Partner will pass ho lding Jx AJxxx Qx Axxx when 5C is on, and will also pass holding Kxx AJxxx x x Axxx when 3NT and 5C have play. You also cannot bid 3D, for partner will p ass with x AJTxx KQxxx xx when 5D should be played. Likewise you cannot bid 3H, for partner will pass when holding Qxx AQJTxxx Q xx when game in hearts will roll home. You should bid 3S to cater for all these possibilities. Clea rly you are insisting on playing in game, and partner will cooperate by bidd ing 3NT if he holds an appropriate stopper and hand. ¨ If you held AQx Qx KJxx KTxx then you are interested in playing a game op posite any hand partner might have, and can bid 3NT to offer him that contra ct (remember he has bid notrumps already, so your stopper needs to be full!) There are a few sequences where the partner of the 2NT bidder has already ha d the opportunity to show values, and has elected to pass. On these occasion s, the level of contract is no longer in question, and a 2NT bid shows toler ance for two contracts. 2NT will be this 2-way \"scramble\" bid only when it i s clear that level of contract cannot be in doubt. These notes are based on thoughts arising from the series in the OKbridge Sp ectator in 1999 (available via http://www.okbridge.com for OKbridge members) on 2NT bids in competition by British expert Marc Smith. Other 2NT cases in competition ¨ When the opponents have opened a weak two or an anchored two-suiter, or s omething similar, then we have Lebensohl continuations after a double. ¨ When the opponents interfere at the two-level over our 1NT bid (or equiva lent) then we have Lebensohl continuations (and whatever doubles we have agr eed). ¨ When we have opened a major suit and they have overcalled below 2NT or ma de a takeout double then responder\'s 2NT shows be an invitational or better hand with at least four-card trump support, and a cuebid shows the same valu es with only three-card trump support. This allows opener to judge the degr ee of fit, which is useful in finding the best game (3NT vs 4 of a major) an d in judging the auction after further enemy competition. The alternate use for the cuebid might be for hands that merely want a stopper to bid 3NT, but these are rare, and can either bid their suit forcing or start with a takeo ut double. The alternate use for 2NT would be natural, but these are again r are, particularly if one excludes six-card minors, four-card majors, three-c ard support and one requires more than a minimal stopper in a hand unsuited for a trap pass. · New suit non-jump bids are natural and forcing or not by agreement. · Jumps in new suits are fit-showing, showing at least four-card trump supp ort and the offensive values to play at the level we have forced our side to play. These are better than jumps showing shortages in the case where we ca n (and should!) anticipate further competition from the enemy. · Jump cuebids of the enemy suit are splinters. ¨ When we have opened a minor suit, responder\'s 2NT can sensibly be played as natural and balanced, with a cuebid showing an invitational or better rai se to three of partner\'s minor suit. The following sections provide clarifications in the various positions and s ome sample auctions. These are provided only for completeness - except for h ands with support for partner\'s suit, they can be derived from the above pri nciples. An exclamation after a bid merely indicates a bid\'s alertable statu s. A bid of 2Y or 3Y is a bid at that level in an unbid suit. Sequences with 2NT bid by advancer · Note that advancer is defined as the partner of the hand to make the firs t defensive action in the auction (see, for example, Auctions 6, 7 & 8). · A free bid by advancer will have values, and that the values are shown by the choice of 2NT or 3-level action. (See footnotes 2 & 3 when raising part ner\'s suit) · When overcaller has shown near opening values or equivalent (2-level over call, takeout double, strong 1NT overcall), then, when holding good values a s advancer, we are concerned about being preempted. Thus 2NT shows a \"bad\" h and and direct 3-level action is a good hand (Auctions 1, 2, 4 & 6). This mi nimizes the effect of opener re-raising preemptively. · From the alternate perspective, when overcaller does not or need not have substantial values, then advancer will wish to act as high as possible with weaker competitive hands to preempt the opponent\'s auctions (Auctions 3 & 5 ). · When the level of contract is not in question, usually because advancer\'s range is known (and weak), then 2NT indicates two possible places to play, and requests overcaller to act as his hand dictates. (See Auctions 7 & 8 in the contexts of Auctions 1 & 2) · The number of suits bid by the opponents is immaterial in deciding the go od/bad status of 2NT, but will affect the type of hands that can be held for the 2NT bids. (See Auction 2 vs Auction 4, and Auction 6) Sequences Meaning 1 1S X 2S X2NT!3Y! ResponsiveBad (competitive to invitational)Good (GF) 2 1S 2H 2S X2NT!3H3Y! Responsive - minorsBad (competitive to invitational)4- card raise Good (GF) 3 1H 1S 2H X2NT!3Y! Responsive - minorsGood (competitive to invitational)Bad 4 1S 2D 2H X2NT!3Y! Heart shortageBad (competitive to invitational)Good (GF) 5 1C / 1D 2S X XX2NT!3Y! BusinessGood (competitive to invitational)Bad 6 1S X 1D2D / 2S PX2NT!3Y! ResponsiveBad (competitive to invitational)Good ( GF) 7 1SP XX 2SP P2NT!3Y This pass limits the hand… (Auction 1)Two places to pl ayClear preference for Y 8 1S2S / P P / 2DX 2H / 2SP P2NT!3Y! This pass limits the hand… (Auction 2) Two places to playClear preference for Y Sequences with 2NT bid by Opener · The same principles apply here as for the sequences for advancer. When re sponder has shown some values then we are concerned about further preemption , and need to act at the 3-level with our good hands. When responder has not shown strength, then we are concerned about being doubled at the three-leve l, and so bid 2NT with our good hands. · Auctions 1-5 are all identical in that responder has taken no action and is probably a poor hand, hence opener needs to be concerned about being doub led at the 3-level for penalties. · In Auctions 6-11, responder has taken some action and opener is now usual ly concerned with further preemption by the opponents, and thus bids good ha nds at the three level to negate this. Sequences Meaning 1 2S P P 1DX2NT!3Y! Spade shortageGood (normal 3-level rebid)Bad (shapely & competing) 2 1S P 2S 1DX2NT!3Y! Spade shortageGood (normal 3-level rebid)Bad (shapely & competing) 3 P / X P 2S 1DX2NT!3Y! Spade shortageGood (normal 3-level rebid)Bad (shapel y & competing) 4 2H P P 1SX2NT!3Y! Heart shortageGood (3-level rebid, e.g. over 1NT respons e)Bad (shapely & competing) 5 P / X P 2H 1SX2NT!3Y! Heart shortageGood (3-level rebid, e.g. over 1NT res ponse)Bad (shapely & competing) 6 2H X P 1S2NT!3Y! Bad (bidding because I have to)Good (better than minimum, or shapely, etc.) 7 2S X P 1D2NT!3Y! Bad (bidding because I have to)Good (better than minimum, or shapely, etc.) 8 1H X 2H 1DX2NT!3Y! Heart shortageBad (better than minimum, or shapely, etc .)Good (GF) 9 P / X 1H 2S 1CX2NT!3Y Spade shortage (or support double)Bad (just competin g)Good (near GF) 10 P / X 1S 2H 1DX2NT!3Y! Heart shortage (or support double)Bad (just compet ing)Good (near GF) 11 X XX 2H 1CX2NT!3Y! Heart shortageBad (just competing)Good (near GF) Sequences with 2NT bid by Responder The same principles apply here as for the sequences for advancer. When opene r has shown some values then we are concerned about further preemption, and need to act at the 3-level with our good hands. Opener is defined to be stro ng once he has opened, so the good 2NT by responder doesn\'t arise. Sequences Meaning 1 1D 2S X2NT!3Y! NegativeBad (just competing, could be weakish)Good (GF) 2 2S 1DX 1SP P2NT!3Y! Bad (forced to bid)Good (interested in things, not for cing) 3 1S 1DX / 2D P2S PX2NT!3Y! Spade shortageBad (just competing, in context)Go od (weird hand - x QT9xx x QJTxxx or xxx KQT9xx x xxx?) Sequences with 2NT bid by overcaller The same principles apply here as for the sequences for advancer. When advan cer has shown some values then we are concerned about further preemption, an d need to act at the 3-level with our good hands. When advancer has not show n strength, then we are concerned about being doubled at the three-level, an d so bid 2NT with our good hands. Typically such auctions only arise when we have started with a double. Sequences Meaning 1 2S X 1SP X2NT!3Y! BadGood (probably strong type for double) 2 2H P 1HP XX2NT!3Y! Takeout of HGoodBad (shapely, competing)
