In contract bridge, the Law of total tricks (abbreviated here as LoTT) is a guideline used to help determine how high to bid in a competitive auction.
It is not really a law (because counterexamples are easy to find) but a method of hand evaluation which describes a relationship that seems to exist somewhat regularly.
Written by Jean-René Vernes for French players in the 1950s as a rule of thumb, it was first described in English in 1966 International Bridge Academy Annals.
[citation needed] In 1981 Dick Payne and Joe Amsbury, using their abbreviation TNT (Total Number of Tricks), wrote at length about it for British readers.
This method works on the assumption that for shapely hands, the combined length of the trump suit is more significant than points or HCP in deciding on the level of the final contract.
[1] In the introduction,[1]: 7 the authors acknowledge Jean-René Vernes as the first writer to investigate TNT (Total Number of Tricks) Theory.
N-S can make 4 spades (conceding two clubs and heart ace) while E-W can make only 1 heart on a good defense (which takes a trump from QJ, two spades, diamond ace and two diamond ruffs)—the law holds, as the total tricks available is 10+7=17.
Note, however, how minor card rearrangements affect the law: There are a number of bridge conventions that take advantage of this principle.