[1] Developed by Marty Bergen and first published in April 1982,[2] 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.
Many partnerships which employ Bergen raises also use Jacoby 2NT and splinter bids in response to major suit openings for game-forcing hands with trump support.
A direct raise to game is then preemptive on a very shapely hand (often with five card trump support).
Some partnerships play an extension of Bergen Raises after opener's bid has been doubled.