The Crash convention was devised by Mr. Kit Woolsey and Mr. Steve Robinson, and is devised as a means to enter the auction with weak two-suited holdings after an artificial 1 Club opening by the opponents. The concept is effective in that the overcall of the intervenor interferes with the line of communication between opener and partner.

And, at the same time, this overcall does not identify the intended two suits, because they are first identified with the rebid of the intervenor. The two-suited holding of the intervenor generally consists of at least nine cards in both suits.

The name of the conventional method is an acronym for: Color, RAnk, SHape. Mr. Kit Woolsey first published an article about this conventional method in The Bridge World. The original version, as published, is presented below.

The original version, as devised and developed by Mr. Kit Woolsey and Mr. Steve Robinson, is presented below and represent the overcalls after the opposing side bids an artificial, strong 1 Club:

• 1 diamond: Promises a two-suited holding of the same color: either red or black, unspecified.
• 1 heart: Promises a two-suited holding of the same rank: either both Major suits or both Minor suits, unspecified.
• 1 spade: This is primarily a preemptive overcall, which can be based on a weak holding and/or a weak Spade suit such as: KJ108. The state of vulnerability is most important in deciding to make this overcall.
• 1NT: Promises a two-suited holding of the same shape: either rounded, Hearts and Clubs, or pointed, Spades and Diamonds.
• Double: Promises a strong holding, either balanced or semi-balance or unbalanced.
• Overcalls: All overcalls on the two level or higher are natural and entirely preemptive.

Opener > Intervenor > Meaning

• 1  club – Strong, artificial opening
• 1 diamond Promises a two-suited holding of the same color: either Red or Black, unspecified.

With either of the two holdings the intervenor can make an overcall of 1 Diamond to show a two-suited holding. In order to discover the intended two suits, the advancer would use the cheapest bid of 2 Hearts asking for clarification. The attempt would be to discover the fit as quickly as possible at the lowest level of bidding.