Thursday, October 20, 2011

Lebensohl

Lebensohl - A comprehensive arsenal of bids designed to handle several difficult auctions, including:
1.
2.
3.
George Boehm originally attributed the convention resolving opponent's notrump interference to Ken Lebensold, who did not wish to take credit for the convention nor request the proper spelling of his name.
Partnership agreement needed:
1. Most play "systems on" over opponents' double: 1N - (X) - ?    Stayman, Jacoby Transfer, etc still on
2. Most play "systems on" over opponents' 2C overcall: 1N - (2C) - ?         Jacoby Transfer, etc still on
3. Basic Lebensohl suggests responder's double of opponents' 2D+ level or above overcall is for penalty, as:
    1N - (2D) - X
    Many advanced Lebensohl players prefer to play responder's double of opponents' overcall is a negative
    double for "takeout", as:
    1N - (2S) - X               Some partnerships play takeout at the 2 level, some at the 3 level but not the 2 level
Note - partner naming conventions seem reversed in Lebensohl discussions when overcaller Doubles.  After partner of the Doubler bids 2 Notrump, it is the Doubler who is known as the "Responder" (of the 2 Notrump bid); accordingly, the 2 Notrump bidding becomes known as the "Advancer".
Assuming overcaller has made a 2 level overcall, Lebensohl allows responder to clarify holdings as: signoff, invitational, forcing one round, game forcing.  Lebensohl also allows responder to show or deny a stopper.  Lastly, Lebensohl has a Stayman-like bidding sequence.  Generally, Lebensohl bidding is based on:
Immediate direct cuebids or jump bid denies a stopper ("fast denies"), while smaller incremental bids show a stopper ("slow shows").  These bids are game forcing.
After advancer (responder) bids 2 Notrump, the opener is forced to bid 3C unless opponent makes an intervening call.  Follow-up bids will indicate the nature of Advancer's hand.
When advancer makes a direct suit overcall at the 3 level, the bid is game forcing.  Thus, Lebensohl does not facilitate responder/advancer invitational bids in a suit below the overcalling opponent.  Experience shows the responder should initially pass (or double for penalty if their system permits), anticipating the 1 Notrump opener will make a suit bid showing a 5 card suit or make a reopening double which permits responder to make a belated call.
When responder bids at the 2 level or advances with 2 Notrump followed by a lower ranking suit than the overcalling opponent,  advancer's suit rebid is signoff.
When advancer bids 2 Notrump and opener puppets to 3C, then Advancer's 3 level bids above the opponents' bid suit are invitational.

1N - (X) - ?
Response
Meaning
2C
Stayman (many play systems on over opponent's Double)
2D/H/etc
5+ card suit (assuming partnership plays "systems on," advancer's (responder's) bid shows the next higher suit), i.e. Jacoby Transfer
XX
Redouble is typically "SOS", forcing opener to bid 2C,
advancer will Pass (showing Clubs and weak hand) or correct to 2D
Pass
Typically "to play" (no desire to escape overcaller's penalty double)
Note: some weak Notrump opener's prefer to play responder's Pass forces opener to Redouble; this allows responder to Pass penalizing overcaller (or hope opponent's will make a call) or responder may bid a longish suit after opener's Redouble.
1N - (2C) - ?
Response
Meaning
X
Typically Stayman (systems on over opponent's 2C overcall)
2D/H/etc
5+ card suit (next higher suit), i.e. Jacoby Transfer
Pass
If opponent's 2C overcall is natural, Pass is "to play". If conventional, Responder may follow up with a natural non-forcing bid
2N
Advancer forces opener to puppet to 3C.  Advancer's rebid above overcaller's suit is invitational
3x
Advancer's 3 level suit overcall is game forcing
1N - (2D) - ?
Response
Meaning
Double
Penalty (however many advanced players now play this as a  Negative Double for "takeout")
2H/S
5+ card suit, to play
2N
Advancer forces opener to puppet to 3C. Advancer rebid above overcaller's suit is invitational
3x
Advancer's 3 level suit overcall is game forcing
1N - (2D) - ?
2N
2N by responder forces opener to relay to 3C
After 1N - (2x) - 2N - (P);
          3C
1N - (2D) - 2N - (P);
3C -  (P)  - ?      
Responder rebids:
Pass is to play.  Responder is showing 5+ Clubs
3D (cuebid) is game forcing with Diamond stopper ("slow shows") and a 4 card major
3H/S, 5 card suit and invitational hand; advancer would have made an immediate 3 level call to show game forcing values
3N, "to play" with stopper in Diamonds ("slow shows");  without a stopper, advancer would make an immediate 3 Notrump call (ostensibly showing a half-stopper or willingness to play in 4 of a minor suit)
1N - (2D) - ?      Responder direct jump bids (without going through 2N) are game forcing:
3C
Game forcing with Club suit
3D
Game forcing with a 4 card major and no stopper in Diamonds - "fast denies"
3H/S
Game forcing with Hearts/Spades
3N
Game forcing and no stopper in opponent's suit ("fast denies")

1N - (2H) - ?      Responder's 2 level suit bids are to play (non-forcing), 2N forces 3C with
                           advancer's follow-up bid is either "to play", "Stayman" invite, or show stopper
                           (further details follow below)
Double
Penalty (however many advanced players now play this as a  Negative Double for "takeout")
2S
5+ card suit, to play
2N
2N by responder forces opener to relay to 3C
After 1N - (2H) - 2N - (P);
          3C -  (P)  - ?
1N - (2H) - 2N - (P);
3C -  (P)  - ?
Pass is to play, showing 5+ Clubs (indirectly bidding a lower suit at the 3 level)
3D is to play, showing 5+ Diamonds (indirectly bidding a lower suit at the 3 level)
3H is Stayman (showing 4 Spades), showing a stopper
3S is invitational, showing 5+ Spades  (indirectly bidding a higher suit at the 3 level)
3N is to play, showing a stopper (indirectly bidding 3N)
3C/D
Invitational, showing 5+ Clubs/Diamonds
3H
Stayman (showing 4 Spades), denying a stopper
3S
Game forcing, showing 5 Spades (jump bid)
3N
Game forcing, denying a stopper ("direct denies")

Opponent makes a preemptive weak 2 bid, with overcaller Doubling

Overcalling partner's 2 level bid is to play

Overcalling partner's 2 Notrump shows a 1 Notrump opener with stoppers in opponents' suit

When overcalling partner makes a takeout Double, with less than 7 points advancer wishes to make a signoff bid involving the Lebensohl 2 Notrump bid.
As before, when opponent overcalls partner's 1 Notrump bid, Lebensohl may be used after opponent opens preemptively with a weak 2 bid and partner doubles. This treatment allows responder to clarify holdings including: signoff, invitational, forcing one round, game forcing.  Similarly, Lebensohl here allows  partner of the Doubler to show or deny a stopper, and continues to allow a Stayman-like bidding sequences.  As we have seen before, Lebensohl bidding is based on:
(2D) - X - (P) - ?
Immediate direct cuebids or jump bid denies a stopper ("fast denies"), while smaller incremental bids show a stopper ("slow shows").  These bids are game forcing.
(2D) - X - (P) - 3D
After partner's Double, the 2 Notrump bid asks opener to bid 3C; however here overcaller may have 17+ points and choose not to accept the 3C puppet transfer.  "Disobedient" follow-up bids show the true nature of overcaller's hand, typically forcing game.
(2D) - X - (P) - 2N;
(P) - 3C
                       Acceptance, willingness to play
(2D) - X - (P) - 2N;
(P) - 3D/H/S/N
           Overcaller has strong interest in game, denying
                                   Advancer's captaincy
Advancer's lowest level bids, those made at the 2 level or beneath 3 of the opponent's bid suit after Responder's 2 Notrump "puppet" are signoff bids.
(2D) - X - (P) - 3C
When Responder bids 2 Notrump and Advancer puppets to 3C, Advancer's 3 level bids above the opponent's bid suit are invitational.
(2D) - X - (P) - 2N;
(P) - 3C - (P) - 3H
(2H) -  X  - (P) - 2N;   
  (P)  - 3C - (P) - ?;   
Advancer Bid After Bidding 2N relay and Responder's 3C response * See Note

Pass, to play showing 5+ Clubs
3H is Stayman, game forcing with stopper ("slow shows")

3S is game forcing showing Spades (overcaller bids 3 Notrump or 4 Spades)
3N shows a stopper without fewer than 4 Spades
* Note: with a strong 17+ point hand, Doubler may deny Responder's 3C bid request after 2N and bid naturally to show extra values.
(2H) -  X  - (P) - ?;     Advancer direct bids without going through 2N show 7+ points (forcing)
3C/D
7-10 points with 5+ Clubs/Diamonds
3H
Stayman, 7+ points and no stopper ("fast denies")
3S
5 Spades, game forcing offering choice of 4S or 3 Notrump
3N
Game values without major suit trump support - "fast denies" stopper

 Opener has made a 2 level reverse bid as:

1D - 1S;
2H - ?

Opener makes a reverse bid showing 17+ points - a 2 level rebid of a rank higher than the 1 level opening bid (assuming responder's bid did not break the 2 level barrier). The responder now has a difficult bidding decision, particularly with minimum hand.   Perhaps the responder only had 5 points with a fair 5 card major suit, evaluating the hand a 6 points adding 1 distribution point.  From the Responder's perspective, game is quite unlikely so responder has interest to signoff below game.  Here, the Lebensohl treatment handles opener's reverse bid, again using responder's 2 Notrump bid (except 2 of opposite major, bidding the fourth suit used when opener bidding begins 1C and rebids 2D):
Bidding
Meaning
1C - 1S;
2H - 2N;
3C - 3S
2N requests opener to bid 3C, allowing responder to make a signoff bid. 
1C - 1S;
2H - ?
Bidding 2S, 3C, or 3D are all game forcing constructive bids.
1C - 1S;
2D - 2H
Bidding 2 of opposite major after opener's 1C -> 2D rebid is Lebensohl. Responder's 2H (fourth suit) is equivalent to 2N in other auctions where opener reverses - in essence, responder cheaper bid of fourth suit or 2N is Lebensohl.
1C - 1H;
2D - 2S
Same as above.   Bidding 2 of opposite major after opener's 1C -> 2D rebid is Lebensohl. Responder's 2S (fourth suit) is equivalent to 2N in other auctions where opener reverses - in essence, responder cheaper bid of fourth suit or 2N is Lebensohl.
1C - 1H;
2D - ?
Similarly, any bid other than the Lebensohl 2S (fourth suit - opposite major) is game forcing.  So if responder bids 2N instead of the fourth suit, the 2N bid is game forcing.  Ditto when responder rebids 2H or any other bid.

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