Good-Bad 2NT 
                    ============

The Good-Bad 2NT is used after competition to show both competitive 
and stronger hands.  After 1S (2H) responder bids suits directly to
show one type of hand and bids 2NT as a puppet to show the other 
types of hands. 

Below is a description of the Good-Bad 2NT convention that was posted
originally on rec.games.bridge.  I've taken the liberty of editing 
the margins, spacings, etc. 

------

   From: hoffman@hal.COM (John Hoffman)
   Subject: Good-bad 2 NT
   Date: 27 Jul 1993 17:28:56 GMT

   The Good-Bad 2NT convention is described by Marty Bergen 
   (Better Bidding Volume 2).  Mike Lawrence has a similar 
   convention with a different name in his most recent book
   on Competitive Bidding.
 
   As used in my partnerships, the convention is used by
   either partner in competitive auctions to distinguish 
   between 

     1. competitive and invitational hands (most frequent)
     2. invitational and game-forcing hands (less frequent)

   Going directly to the 3 level instead of using Good-Bad 2N 
   shows invitational values in case 1, and shows game-forcing 
   values in case 2.

   The Good-Bad 2N bid is artificial and shows a hand with
   the lower of the 2 possible value ranges in each case.  It 
   is nominally forcing, and nominally relays to 3C (allowing 
   the NT bidder to pass or select a signoff location).  In 
   some cases, partner will correctly refuse to relay to 3C.

   Our rules for when it applies differ somewhat from 
   Bergen's.  We play that it is on under these conditions:

     1. RHO's most recent call is a suit bid at the 2 level
     2. our side has made at least one bid which is not a pass
     3. the bid is obviously needed to distinguish the value ranges.

   A few typical examples of Good-Bad 2N (opponent's bids 
   in parentheses)...

   1H - (p) - 1N - (2S) - ??
      3H = invitational values, natural
      3C/3D = invitational values, natural
      2N = Good-Bad 2N: competitive values, with suits unspecified

   (1S) - DBL - (2S) - ??
      3C/3D/3H = invitational values
      2N = Good-Bad 2N

   (1C) - DBL - (1S) - p; (2S) - ??
      3C/3D/3H = invitational values (opposite a pass:
               this should be a very strong single-suited hand)
      2N = good-bad 2N (strong single-suited hand willing to compete)

   1H - (1S) - 2D - (2S) - ??
      3C/3D/3H = game-forcing
      2N = Good-Bad 2N, only invitational opposite a minimum 2D bid

--- End of Hoffman's post ---


Marshall Miles suggests in "Competitive Bidding in the 21st Century" 
to invert the meanings of the direct bids and 2NT.  Thus the direct
bids are weak, and the 2NT bid shows strength.  This inversion allows
the "weak" hands to be shown, which may be needed as a lead director.
Furthermore, after the 2NT bid by opener, responder completes the 
relay to 3C to show *good* hands (since opener will never pass the
3C puppet) and other bids show bad hands.