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
Contract bridge is this mixture of information exchange and evaluation, deduction, and tactics that is at the heart of bidding in bridge. A number of basic rules of thumb in bridge bidding and play are summarized as bridge maxims. A "bidding system" is a set of partnership agreements on the meanings of bids. A partnership's bidding system is usually made up of a core system, modified and complemented by specific conventions (optional customizations incorporated into the main system for handling specific bidding situations) which are pre-chosen between the partners prior to play. The line between a well-known convention and a part of