LEBENSOHL CONVENTION

The origin of the Lebensohl convention seems to have been lost to history, according to Mr. Edgar Kaplan. In the late 1960s, the convention began appearing on different convention cards, although written in by hand. At first, it was believed to have been devised by Mr. Kenneth W. Lebensold, born in 1947, of Oakland, California, a mathematics professor, and who had won several major bridge competitions, going under the assumption that the name had been misspelled. But Mr. Kenneth Lebensold demonstrably denied any and all contribution. It was Mr. George A. W. Boehm, 1922 to 1993, of New York City, who was a retired editor, mathematician, graduate of Columbia University, writer for the magazines Fortune, Newsweek and Scientific American and for The Bridge World, who published an article about the convention in The Bridge World magazine in November 1970, and, for a lack of anything better, called it the Lebensohl convention.

The concept behind Lebensohl was the result of the following difficulty in bidding after an intervening overcall after your partner has opened the auction with 1 No Trump. The examples should clarify this point.

North	East	South
1 NT	2	84 653 8 QJ107654
		3		1. A sign-off? Forcing?
		3		2. Stayman? Forcing?

North	East	South
1 NT	2	KQ 87 AQJ987 K108
		3		1. A sign-off? Forcing?
		3		2. Stayman? Forcing?

After realizing the difficulties in responding, the questions become whether or not the first response is a:

1. forcing response

2. non-forcing response

3. natural response

4. artificial response

5. invitational response

North	East	South
1 NT	2 ///	Double		is for penalty
	2	2 //		is to play
	2 /	2 /		is to play
	2 //	2		is to play
	2	3 //		is forcing to game
	2 /	3 /		is forcing to game
	2 //	3		is forcing to game
	2 ///	2 NT		forces partner to rebid 3

The rebids by the responder after 3 Clubs by his partner:

1.	Pass with a weak hand and long Clubs.
2.	Any bid suit below the rank of the overcall is a sign-off.
3.	Any bid suit above the rank of the overcall is invitational.

Any immediate cuebid of the suit of the opponent is Stayman and promises a good 9 high card points count. Any immediate cuebid promises a 4-card Major suit, but it is important to remember that the cuebid also denies having a stopper in the suit bid by the opponent. This cuebid by the responder is forcing to game unless the partnership can not find a Major fit.

North	East	South
1 NT	2	3		Stayman
	2	3		Stayman
	2	3		Stayman, showing a 4-card Spade suit
	2	3		Stayman, showing a 4-card Heart suit
				ALL CUEBIDS DENY A STOPPER.

The options for the No Trump bidder, after a cuebid by his partner, are:

1.	to bid a 4-card Major, if he has a 4-card Major.
2.	to bid 3 No Trump with a stopper in the suit of the opponent.
3.	to seek a better contract, if neither condition is fulfilled.

3.1.	With a minimum No Trump, bid 4 Clubs or 4 Diamonds.
3.2.	If the 4-card Major suit of the responder is known, then the No Trump bidder can consider playing in a 4-3 Major fit.
3.3.	Holding a maximum No Trump and no wasted strength in the suit bid by the opponent, a jump to five of long Minor suit is advisable.
3.4.	Cuebidding the suit of the opponent at the Four Level is requesting the partner to choose his better Minor suit at the Five Level.

Any 3 No Trump response after any intervening overcall promises sufficient values and no 4-card Major suit, but it also denies having a stopper in the suit bid by the opponent. The No Trump bidder has then several options:

If the responder bids 2 No Trump after an overcall, forcing his partner to rebid 3 Clubs, and then cuebids the suit of the opponent, then this cuebid is a Stayman bid, asking for a 4-card Major suit. The difference in this bidding sequence is the fact that the responder is showing a stopper in the suit of the opponent.

Assuming the following bidding sequence:

North	East	South	West
1 NT	2	2 NT	Pass
3	Pass	4			Cuebidding = Stayman
					Shows a stopper.

demonstrates that this cuebid by the responder on the four level is also Stayman, bypassing the possibility of a 3 No Trump contract, and whether such a bidding sequence is advisable, is a matter of partnership agreement.

North	East	South	West
1 NT	2 ///	2 NT	Pass
3	Pass	3 NT			Shows a stopper.

The bidding sequence by the responder above shows a stopper in the suit bid by the opponent and requests that partner should pass the final contract of 3 No Trump.

Most partnerships play that if there is no intervening overcall, then the bid of 2 No Trump retains its original meaning.

The advantages are that each response can be recognized and determined as to whether they are:

1.	Forcing.
2.	Invitational.
3.	Non-forcing.
4.	Game-forcing.

North	East	South
1 NT	3	3 //		one-round forcing
	3	3 /		one-round forcing
	3	3		one-round forcing
	3 ///	Double		Negative Double, not Penalty Double
	3 ///	5 /		Game sign-off
	3 ///	4 /		Game sign-off
	3 ///	3 NT		Game sign-off
	3 /	4 /		Stayman
		or		Slam interest, and may have a 4-card Major suit

If the overcall on the three level is doubled by the responder, the opener must bid unless the better option is to convert the takeout double for penalties, which is possible when holding a maximum No Trump.

If the responder bids 3 No Trump after a three level overcall, then this response can either show or deny a stopper in the suit bid by the opponent. This is a matter of partnership agreement. Several partnerships bid 3 No Trump, which shows a stopper, and use the Negative Double to deny a stopper.

Some of the defense mechanisms employed by the opponents after a 1 No Trump opening are natural and some defense mechanisms are artificial. It is important for the partnership to recognize which overcall is natural and which is artificial, which defense shows a two-suited holding and identifies both suits, which defense shows a two-suited holding and only one identified suit, which defense shows a two-suited holding and both suits are unknown, and which defense uses a double to show a one-suited holding. The partnership should understand these concepts. Several of the more popular conventional methods are listed below:

D.O.N.T.	Bergen Over No Trump	Hamilton Convention
Astro Convention	Cansino Convention	Landy Convention
Modified Astro	Cappelletti Convention	Ripstra Convention
Pinpoint Astro	Crash Over One No Trump	Suction Convention
Astro Cuebid	Brozel Convention	Becker Convention
Aspro Convention	Brozel Rescue Bids	Optional Double

1.	In the case that the artificial overcall shows two identifiable suits, then the cheaper cuebid is game invitational. The higher cuebid is then game-forcing. After this bidding sequence, all Lebensohl guidelines are system on.
2.	In the case that the artificial overcall shows only one identifiable suit, then the known suit can be used for the cuebid. After this bidding sequence, all Lebensohl guidelines are system on.
3.	Unless the artificial overcall shows both Major suits, then cuebids are used as Stayman and all Lebensohl guidelines are system on.
4.	If the partnership can apply the 2 No Trump response, then all delayed cuebids either show or deny stoppers in the suit(s) of the opponent by partnership agreement.
5.	The four level jumps by the responder are normal and all Lebensohl guidelines are system on. However, four level non-jumps are natural game-forces and/or cuebids.
6.	Any double after an artificial overcall are considered to be natural and indicates defensive values in one or both of the suits indicated by the overcaller. A redouble after an artificial double by the opponent promises a moderate to good holding.
7.	After an artificial overcall and a pass by the responder, any Delayed Double is for penalty. Any Delayed Suit Bid is considered competitive and is either a sign-off or lead directing for the partner.
8.	In general, any artificial double by the overcaller should not interfere with the employment of the Lebensohl convention and is treated as if there had been no double.
9.	After an artificial 2 Clubs overcall, a double is Stayman, and otherwise the overcall is treated as if there had been no double.
10.	If the responder initially passes the artificial overcall, then this pass becomes a Forcing Pass, and the partner is forced to find a rebid, double and/or redouble, or bid a 5-card suit if possible.

These are general guidelines and should be considered in this context. The partnership must become acquainted with the different defense mechanisms of the opponents and adjust their partnership agreement accordingly. The defense against Landy, for instance, may not work against Brozel.

After the opponents have opened the auction with a Weak Two Bid and your partner doubles, defensive guidelines are necessary to inform your partner whether or not you, who are forced to bid, have a weak holding, a moderate holding or a strong holding. The Lebensohl convention can assist greatly with this dilemma. The following guidelines should clarify.

Lebensohl After A Takeout Double of a Weak Two Bid

1. The 2 No Trump response by the responder forces the partner to rebid 3 Clubs. This gives the responder the opportunity to sign off in a long suit with a weak holding, and the partner must pass.

2. A non-jump suit bid by the responder at the three level is constructive and informs the partner that his holding contains useful values and/or suit length and/or distribution.

This situation arose after such bidding sequences and holdings were encountered, such as the following:

North	East	South	West
2 //	Double	Pass
			754 86 109764 985
			865 K7 KQJ86 1082

Since West is forced to bid after his partner has doubled, the difficulty was to discover a method of communicating a very weak holding as compared with a holding with moderate, perhaps excellent values and/or distribution. Using the guidelines of the Lebensohl convention clarifies the distinction between these two circumstances. The partner may have a minimum for his Takeout Double, but gains the necessary information from his partner as to how to proceed. The partner may also have a holding with excellent values, but needs the information from his partner about his holding in order to perhaps place the contract. The Lebensohl convention is the bridge tool, which allows the partnership to do this.

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