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
Skat (card game) (in case of a "hand" game, when the "Skat" is not picked up). Players have therefore to exercise careful scrutiny during bidding, as not to incur an unnecessary loss. The bidding may also give away some information about what cards a player may or may not hold. Experienced players will be able to use this to their advantage. The game value (also called "hand value", ) is what the game will be worth after all tricks have been played. It is determined not only by the 10 cards held, but also by the two-card "Skat". The "Skat" always belongs to