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
Hand evaluation excess of 3 in the suit; for short suits only clear winner combinations are counted: An Acol strong 2 of a suit opening bid is made on 8 playing tricks (Landy 1998) This statistically derived method for evaluating Contract Bridge hands was developed by Zar Petkov. It attempts to account for many of the factors outlined above in a numerical way. A key differentiator between the bidding effectiveness of experts versus laymen is the use of hand visualisation during all stages of bidding. In his book "The Secrets of Winning Bridge", Jeff Rubens advises to focus on just a few