Source: Wikipedia
In contract bridge, Bergen raises are conventional treatments of responses to a major suit opening in a five-card major system. Developed by Marty Bergen and first published in April 1982, Bergen raises are based on the Law of total tricks, a hand evaluation concept which states that with a combined nine trumps in the partnership one should compete to at least the three-level regardless of combined high card strength. Bergen recommended that instead of the more rare occurrence in the use of the 3 and 3 response as a jump shift to show a strong hand, these bids should be redeployed to provide more precise information about the length and strength of support held by responder for partner’s five-card major suit opening when responder has four-card support. Bergen raises are used in response to a 1or 1opening bid to show hands of specific length in trump support and strength as follows:- 1NT followed by 3/3♠ on next round – invitational to game (typically 11-12 high card points) with three-card support
- 2/2 – weak (7-10 high card points) with three-card support
- 3 – weak (typically 7-10 high card points) with four-card support
- 3 – a limit raise (typically 11-12 high card points) with four-card support; invitational to game
- 3/3 – very weak (preemptive, typically less than 7 high card points) and four-card support
- 4/4 – very weak (preemptive, typically less than 7 high card points) and five-card support