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
Bidding system suit. Natural systems generally use opening bids as follows: The most widespread natural systems are: Various developments in the area of natural systems have resulted in systems that are natural in essence, but contain special features. Examples are systems like Romex, Boring Club, Fantunes, and EHAA (Every Hand An Adventure). Artificial systems can be further classified into: Bidding system A bidding system in contract bridge is the set of agreements and understandings assigned to calls and sequences of calls used by a partnership, and includes a full description of the meaning of each treatment and convention. The purpose of bidding