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
History of contract bridge auction bridge made by Harold Stirling Vanderbilt and others. The most significant change was that only the tricks contracted for were counted below the line towards game and slam. That made bidding much more challenging and interesting. Another innovation was the concept of "vulnerability", a difference in the sizes of penalties incurred by partnerships that have or have not won one game. That discouraged sacrifice bidding to protect the lead in a rubber. Some other scores were adjusted to produce a more balanced game. Vanderbilt set out his rules in 1925, and within a few years contract bridge had so