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
Auction bridge Auction bridge The card game auction bridge, the third step in the evolution of the general game of bridge, was developed from straight bridge (i.e. bridge whist) in 1904. The precursor to contract bridge, its predecessors were whist and bridge whist. Auction bridge trick scoring, bonus scoring, and penalty scoring are radically different from contract bridge, and there is no concept of vulnerability in auction bridge. Bidding rules are nearly the same, although in contract bridge bidding many complex artificial bids and bidding systems have evolved. It is not certain to whom auction bridge should be credited. A letter in