Келісімдік бриджде қол бағалау әдісі: Жеңіліс трюктерінің саны

Method of hand evaluation in contract bridge
In the card game contract bridge, the Losing Trick Count (LTC) is a method of hand evaluation that is generally only considered suitable to be used in situations where a trump suit has been established and when shape and fit are more significant than high card points (HCP) in determining the optimum level of the contract. The method is generally not considered suitable for no trump or misfit hands; also, the trump suit is generally considered to require at least eight cards in length with no partner holding fewer than three. However, the LTC method of hand evaluation has been used successfully to evaluate unbalanced and balanced opening hands, and overcalls, since 1938 (combined with ‘quick trick’ evaluation and defined biddable suits), and by itself since 2017, before a fit and trump suit have been established based on the premise that a fit could usually be found later. Based on a set of empirical rules, the number of "losing tricks" held in each of the partnership's hands is estimated and their sum deducted from either 24 (the result is the number of tricks the partnership can expect to take when playing in their established suit, assuming normal suit distributions and assuming required finesses work about half the time)

Whichever method is being used, utilizing LTC evaluation need not stop after the opening bid and the response. Assuming opener bids 1 and partner responds 2; opener will know from this bid that partner has 9 losers (using basic LTC), if opener has 5 losers rather than the systemically assumed 7, then the calculation changes to (5 + 9 = 14 deducted from 24 = 10) and game becomes apparent! A small number of modern bidding systems systemically utilize multiple responses and rebids after the opening bid to refine LTC evaluation and to allow further adjustments to be made based on combined suit length, shortages found, and high cards held. The Imperspicuity losing trick count bridge bidding system uses the Law of Total Losers, shape asking relay bidding, loser asking relay bidding, CROSS and CRO relay bidding, and LTC techniques, to systemically determine the final bidding level, after opening bids and overcalls are initially made based on LTC evaluation methods.

All LTC methods are only valid if trump fit (4 4, 5 3 or better) is evident and, even then, care is required to avoid counting double values in the same suit e. g. KQxx (1 loser in LTC) opposite a singleton x (also 1 loser in LTC). Regardless which hand evaluation is used (HCP, LTC, NLTC, etc.) without the partners exchanging information about specific suit strengths and suit lengths, a suboptimal evaluation of the trick taking potential of the combined hands will often result. Consider the examples:

Both layouts are the same, except for the swapping of West's minor suits. So in both cases East and West have exactly the same strength in terms of HCP, LTC, NLTC etc. Yet, the layout on the left may be expected to produce 10 tricks in spades, whilst on a bad day the layout to the right would even fail to produce 9 tricks. The difference between the two layouts is that on the left the high cards in the minor suits of both hands work in combination, whilst on the right hand side the minor suit honours fail to do so. Obviously on hands like these, it does not suffice to evaluate each hand individually. When inviting for game, both partners need to communicate in which suit they can provide assistance in the form of high cards, and adjust their hand evaluations accordingly. Conventional agreements like helpsuit trials and short suit trials are available for this purpose.