of most value in competitive bidding situations where the HCP are divided roughly equally between the partnerships. LoTT is said to be most accurate when the HCP are fairly evenly divided between the two sides and the bidding is competitive. Experts apply adjustment factors to improve accuracy. TNT (Total Number of Trumps = Total Number of Tricks) Payne and Amsbury's Bridge: TNT and Competitive Bidding (1981) may have been the first major book on the topic. In the introduction, the authors acknowledge Jean-René Vernes as the first writer to investigate TNT (Total Number of Tricks) Theory. Page 19 includes a key table that may not have been printed elsewhere. Total trumps principle By combining LoTT with the scoring table, it is argued that the following Total trumps principle is quite often a winning strategy: Bid to a number of tricks equal to the number of trumps you and your partner hold (and no higher) in a competitive auction. Thus, if with an eight-card fit, a pair is safe to bid to the two level but are unsafe to go to the three level. But, with a nine-card fit, the three level will be safe. In this context, "safe" does not necessarily mean that the contract will be made. But if not, it means that it is a worthwhile sacrifice against the opponents' contract. For example, if the opponents have bid to two spades, and you have a nine-card heart fit, the "law" says you should bid three hearts. Assuming the opponents have an eight-card spade fit, there are 17 total tricks. If the opponents can take eight tricks, LoTT says you can take nine. If the opponents can take nine tricks, LoTT says you can take only eight. But down one (even doubled, if not vulnerable) is a smaller negative score for you than letting the opponents make three. Derived from LoTT, this principle assists players in judging the level to which they should bid in a competitive situation. At its simplest a player should bid to the level of their calculation (from the bidding) of the number of trumps held by their side: When the balance of HCP is unfavourable, bidding to this level will act as a useful sacrifice When the balance of HCP is favourable, bidding to this level will be an achievable contract When the HCP are fairly equally split between the two sides, bidding to