From: willey@lard  (Richard E. Willey)
Subject: Re: Bergen 2 under
Date: Fri, 09 Dec 1994 10:18:32
Organization: FTP Software, North Andover, Massachusetts

DMFV47A@prodigy.com (Kent Burghard) writes:

>    From The Official Encyclopedia of Bridge, Fifth edition:
>    
>    Two-Under Transfer Preempts
>         Preemptive openings of 3C and higher can be used to show the suit
>         two steps higher than the one bid.  For example:
>          a)  S 6                                     b)  S 65
>              H QJT8632                                   H KQT8632
>              D 87                                        D K87
>              C 973                                       C 3
>         These are possible 3H bids, but are substantially different in 
>    playing
>    strength.  If 3H is bid with both hands, the responder will often have 
>    to
>    guess.  Bidding 3C to show a 3H opening allows the responder to bid
>    3D if he wishes to invite 4H.
>         This has the usual advantage of transfer bids, in that partner 
>    becomes
>    the declarer and the lead comes up to his possible tenace position.  A
>    disadvantage is that it places less pressure on the opponents in the
>    bidding: Second hand will have two opportunities to act.  (Devised by
>    Marty Bergen.)
    -
    

a couple other minor points.
2 under preempts, as originally devised by Bergen start using a 2D preempt to
show a "typical" 2 spades preempt.  Bergen uses a strong 2C bid, so 2H is
natural.  2S shows a 3C preempt, and so on up the line.

As I understand the system, the major drawback to the 2 under preempt is that
it does not pressure the opponents nearly as much as a typical preempt.  Bergen
claims that this is balanced by the ability to open a 2 under preempt on much
weaker hands than a corresponding "natural" preempt.  For example, Bergen would
sometimes consider S T98xx as a sufficiently strong suit to hazard a weak 2 
bid.  This hand, however, would be opened 2D.

In responding to 2 under preempts, bidding the intermediate suit is the only
forcing bid, and requests that opener describe his hand.  All other bids are
non-forcing.

If you're interested in more details, the only really detailed descriptions of
the Bergen 2 Under preempt that I've run across is a short treatment in 
Preempts from A to Z by Ron Anderson and Sabine Zenkel.  The authors also 
sugeest some worthwhile defenses to the system.

Please note, that 2 under preempts are considered a superchart convention.  
Unless you are playing at this level, you probably won't need to spend much
time worrying about them.