Contract bridge grand slam exists. The modern game of contract bridge was the result of innovations to the scoring of auction bridge by Harold Stirling Vanderbilt and others. The most significant change was that only the tricks contracted for were scored below the line toward game or a slam bonus, a change that resulted in bidding becoming much more challenging and interesting. Also new was the concept of "vulnerability", making sacrifices to protect the lead in a rubber more expensive. The various scores were adjusted to produce a more balanced and interesting game. Vanderbilt set out his rules in 1925, and within
Optimum contract and par contract value of the bonuses (especially when vulnerable). In duplicate pairs scoring, the subtle difference between a major suit game, a NT game and a minor suit game make the declaration an important decision. Each side has its own optimum contract and, for a side with poor hands, "pass" may be the optimum call. Where there is competitive bidding (i.e. both sides are bidding) the extra dimension of sacrificial bidding is added, and the theoretical optimum contract can be overtaken by the par contract. The par contract on a deal is that contract that results from optimal bidding by both sides