The One Notrump Battlefield – Competing against 1NT opening bids and handling the competition by the opening side. – Prepared by Jon Gustafson (June, 2009)


There is an ongoing bridge convention arms race that has been waged from the mid-1940s.  Until Alvin Landy developed his convention for showing the majors after a 1NT opener, the opponents were expected to show their respect for an opening bid of 1NT by passing.  For the next few decades the battle had been primarily on the defensive side of the field.  A long and growing list of conventions for competing against a notrump opener has been in use.  But the opposition has countered with an array of tools designed to hold the defensive intruders at bay.  This lesson is a survey of how to compete and how to handle the competition after an opening one notrump.

Defensive Objectives after a One Notrump Opening Bid.

In the early days a 1NT opener was 16-18 HCP.  Today 15-17 is most common, while not a small number of pairs use weak notrumps of 11-14 or medium notrumps in the ranges 13-15 or 14-16.  You may also encounter light 10-12 and even the ultra-light 8-10 notrump openers.  Defensively, you need to be prepared for three different notrump ranges:

Strong (and Medium) Notrump – any range which includes 15 HCP.

Weak Notrump – within the range of 10-14 HCP.

Ultra-Light Notrump  – within the range of 8-10 HCP.

After a 1NT opener there is not much room to maneuver.  Effective competition requires getting in and out at the two level.  Possible defensive actions include:

Penalty Double – requires at least the upper end of the opened NT range and a good suit to lead.

Natural Overcall – a good six card suit and some scattered strength (see Rule of Eight).

Conventional Bid - showing 2 or more suits with suitable strength (also see Rule of Eight). A hand with a single suit of 5 cards occurs in 15% of hands; a single suit of 6 cards occurs in 9% of all hands. However, a hand containing 5-4 suits occurs in 23% of hands.

Pass – with no long suit or promising distribution and not enough strength for a penalty double.

Mel’s Rule of Eight[1] – Take the total number of cards in your two longest suits and subtract the number of losers using the LTC method.  If the answer is 2 or higher, bid something.  If the answer is 1 or zero then pass.  This will get you into the ball park of when to compete and when to pass based on top honors and distribution.  Safety is an additional factor, not fully addressed by the Rule of Eight.  A disaster looms when the suits you hold break badly.  The counter to this is to have texture in the suits – packed with secondary honors and intermediates. 


Counting Losers


missing the queen

one loser


missing the ace and queen

two losers


missing the ace and king

two losers


missing the ace

one loser


six losers

Rule of Eight Examples:

Example 1

Example 2

Example 3

Example 4


* AQ865


* 76

* K7532

* K8654

* 43

* 7

* AKJ73

* Q82

* Q7

* K65

* Q76

* AK3

* A10654

* 85

Example 1 – There are eight cards in the two long suits but seven losers (two each in spades, diamonds and clubs and one in hearts). You should pass despite the 12 high-card points and five-card major.

Example 2 – You have 10 cards in your two long suits and seven losers (two each in spades, hearts and diamonds and one in clubs). The difference is three, so the rule says should get in there. It's only 6 HCP, but distribution is the key.  However, you are completely at the mercy of how these suits break with such lousy texture.

Example 3 – From the 2000 Bermuda Bowl, Paul Soloway held this hand and heard Brazil's Roberto Mello open 1NT (15-17) on his right.  Did Soloway bid or pass?  Mel's Rule of 8 suggests a pass: eight cards in the two longest suits minus seven losers equals one, so pass is recommended despite the 15 HCP and nice spade suit.  Soloway did indeed pass and defeated 1NT two tricks.  Soloway had not heard of the Rule of 8, but he did what it suggests nonetheless.

Example 4 – Here is another example from the Silver Ribbon Pairs at the 2007 Spring Nationals.  With a strong 1NT opener on his right, a player held this hand and entered the auction with a natural bid of 2¨.  The result was a doubled contract and a score of minus 800, what he deserved. With a five-card suit and a flat hand, he should have opted for defense.  If you use the Rule of 8, it will tell you when and when not to bid over their 1NT, and you will avoid disasters of this type.

Defensive Agreements after a One Notrump Opening Bid.[2]

Consider the following hands after your RHO opens the bidding with a strong 15-17 notrump at equal vulnerability.  What you would bid using each of the defensive agreements 1) through 7) below?

Hand A

Hand B

Hand C

Hand D

Hand E

* KQ9876

* A65

* 76

* A7

* KQ987

* A965

* 76

* A7

* KQ98

* A965

* 6

* AJ74

* 98

* 9

* AQ876

* AQ854

* 98

* AQ876

* 9

* AQ954

1)      Natural – Used against strong and weak, in both direct and balancing seats.  All overcalls are natural and double is penalty.  This agreement works fine with single suited hands such as A, but not for any of the other two or three suited hands.  Unless you can show your distribution at the two level you can not be sure of finding your best fit without getting too high.  None of the hands is strong enough for a penalty double.

2)      Landy – Used against strong and weak, in all seats.  Double is penalty; 2 shows both majors, at least 4-4 but usually at least 5-4.  All other bids are natural.  Responder usually bids their better major, but at the expense of responding 2 naturally, the 2 response can be used to show equal length in the major allowing the overcaller to guarantee playing in the best major fit.  The Landy convention works well with hands A & B and with hand C if you allow 4-4 in the majors, but you cannot satisfactorily handle hands D & E.

3)      Cansino – Used against strong and weak, in all seats.  Double is penalties; 2 shows a hand playable in ’s and two other suites.  2 shows both majors and all other bids are natural.  This defense works well with single major suited hands (hand A) and very well with many 3-suited hands (hand C) except those with short clubs.  A problem is that you may find yourself playing in 2 or 2 when there is a better major suit fit.

4)      DONT – Used only against strong notrumps in all seats.

DBL   =    a single suited hand

2     =    ’s and another suit

2     =    ’s and a major

2     =    both majors

2     =    ’s (a weaker hand than double followed by a  bid).

One advantage of using DONT is that all two-suited hands have the potential of being shown, although only the majors are shown explicitly.  There is a bid for every hand A through E.  Because not all suits are shown at once, including single-suited hands, huge fits might go undiscovered.  Keeping one suit hidden might be a limited advantage if the opening side declares.  You may find yourself in a minor suit contract when there is a major suit fit when a 2/ overcall is passed out.  The biggest advantage, as advertised, probably is disrupting the opponent’s notrump conventions.

5)      Cappelletti/Hamilton – Used against both weak and strong notrumps in all seats.

DBL   =    penalties

2     =    a single suited hand, usually a major but not necessarily.

2     =    both majors, at least 5-4

2     =    ’s and a minor

2     =    ’s and a minor

2NT   =    both minors

Cappelletti/Hamilton is more versatile than DONT in part because the penalty double is available against weak notrumps.  It also discloses the more important major suits in two-suited hands.  There is a bid for every combination of hands A through E.  The response to 2 is that advancer usually bids 2 which overcaller will pass or correct to his suit.  The main disadvantage is the inability to show a single-suited major hand quickly.  In response to 2 showing both majors advancer bids his best major, but the best major fit may not be found.  This is probably the most popular convention in the U.S.

6)      Astro – Used against both weak and strong notrumps in all seats. 

DBL   =    penalties

2     =    ’s and a minor

2     =    ’s and another suit (which could be hearts)

2     =    ’s

2     =    ’s

2NT   =    both minors

Distribution for the 2 and 2 bids should be at least 5-4 in the two suits or possibly 4-4-4-1 shape.  Astro has an even stronger emphasis on the majors and overcomes the ineffectiveness of many systems to introduce a single-suited major hand.  Astro and it many variants are popular among experienced players, although the national and international experts that dominate the ACBL national tournaments each seem to have their personal favorites.

7)      Grano-Astro – Used against strong notrumps in all seats. 

DBL   =    ’s and a lower suit

2     =    ’s and ’s

2     =    ’s and ’s

2     =    ’s

2     =    ’s

2NT   =    both minors or a huge two-suiter.

Distribution for the 2 and 2 bids should be at least 5-4 in the two suits or possibly 4-4-4-1 shape.  Grano-Astro is a refinement of Astro with many of the benefits of Astro but also names both suits when hearts are held (see hand E).  Its focus is less on disruption and more on winning part score competitive battles.

8)      Ultra-Light Notrump Defense – used specifically against very weak notrump openers in the range of 8-10 HCP.  Double shows a strong notrump opener, any distribution.  You would have opened 1NT.   Advancer can pass for penalties or, use the entire 1NT bidding structure just as though 1NT had been opened.  All other suit bids are natural and show a good overcall.

This is just a few of the many dozens of defenses to one no trump openers.  Most of these agreements with the exception of DONT handle the major suit combinations well.  Cansino and DONT can introduce the most combinations of suits but are pretty ineffective at actually finding useful fits.  There main value is to get in, disrupt and get out, without really trying to complete.  Cappelletti/Hamilton and Astro revolve around the major suits, treating the minors as spots of last refuge if a major fit does not materialize.  Grano-Astro is similar to another class of conventions such as Pin-point Astro and Brozel (neither described) which tries to explicitly introduce both suits in a two-suited hand.  This makes finding a fit quicker and easier and is therefore more effective at competing.  But this is only accomplished by not explicitly handling every two suited combination.

The follow up bids by the advancer for most of the conventions can be complex.  For example, a 2NT bid by advancer is generally used to signal a strong, distributional hand with interest in game.  These agreements are not covered here but must be learned to use these conventions well. 



Agreements for Countering Competition after a One Notrump Opening Bid

Just as the choice of agreements for completing against a 1NT opener depend upon what you are trying to accomplish, the ways of handling competition depend upon your objectives.  All of the following seem to be issues when dealing with the disruption.

-        Ignoring the pesky opponents, as though they didn’t exist

-        Penalizing the interferers when possible

-        Competing effectively in the battle for a part score or more

-        Escaping from a penalty double

1)      Mirror Doubles / Stolen Bids[3] – After an opening 1NT bid if an opponent bids 2 then double is Stayman, if an opponent bids 2 then double is a transfer to hearts and if an opponent bids 2 then double is a transfer to spades.  And further, all higher bids retain their same meaning as though no interference had occurred.  The goal using this agreement is to make the opponents go away.  Just as if they were silent.  But is this such a good idea?  Haven’t you learned something about the opponent’s hands?  Is there a juicy penalty waiting?  Should you be forewarned of a running suit should you end in a notrump contract?  In spite of the popularity of this convention, is sticking your head in the sand the best approach?  Part of the answer depends upon how useful other meanings of doubles or simple suit bids can be, considered next.

2)      Doubles in Competition[4] – After an opening 1NT bid is overcalled a double has several possible meanings:

-        The default meaning of the double of an overcall (no matter what the overcall shows) is penalty.  By default we mean that in the absence of any discussion or expectation about the meaning of the double with your partner.

-        Many choose to use the double of a 2 bid as Stayman, but do not use any other form of Mirror Doubles / Stolen Bids.

-        Until they past few years, many players played penalty at the two level and negative doubles at the three level.

-        There is trend toward playing that all doubles are negative, takeout for the un shown suits.  A corollary of this agreement is that the negative double tends to shows shortness in the opponent’s suit(s), so with length and a desire to defend a doubled contract, you must pass.  Your partner will hopefully reopen with a double when short in the opponent’s suit.

-        In response to the many conventions showing two-suiters, a useful agreement is that the double of one-suiters are negative, doubles of two-suiters are penalty (showing defense against at least one of their suits) and three level doubles are negative.

3)      Simple Suit Bids in Competition[5] – After an opening 1NT bid is overcalled, a suit bid at the two level is natural and to play and three level bids are forcing.  Rather than being a transfer it is very useful to be able to compete for a part score and still be able to make forcing bids, exploring the best contract.  The obvious problem is we need a way to make an invitational bid.  That’s where the 2NT lebensohl convention comes in, next.

4)      The lebensohl Convention[6] – Incorporating 2) and 3) we are able to respond to competition at the two and three level, showing non-forcing and forcing strength hands, but it appears we have run out of space.  How do we invite?  We do have a 2NT bid available.  In the old days this showed 8-9 points opposite a 15-17 opening notrump.  Can we do without it?  We will discover that what we gain is much more valuable than the loss.  After a 1NT opener and a natural overcall,

  1. Doubles are negative at the two and three level.
  2. At the two level a suit bid is to play.
  3. At the three level a suit bid is forcing to game.
  4. 2NT is an artificial relay to 3. Responder’s rebid over 3 are,

a.       Pass with a weak hand and long clubs.

b.      Any suit below the rank of the overcall is a signoff.

c.       Any suit above the rank of the overcall is invitational.

  1. An immediate cue bid by responder is Stayman.  It promises at least one four-card major and denies a stopper in the enemy suit.
  2. A direct jump to three notrump denies a stopper in the enemy suit.
  3. 2NT followed by a cue bid is Stayman and shows a stopper in the enemy suit.
  4. 2NT followed by 3NT shows a stopper in the enemy suit.

After artificial overcalls showing two-suiters where only one of the suits is known, lebensohl is used and the known suit serves the same function as a naturally overcalled suit.  If both of the suits are known strong hands can use unusual vs. unusual to show responders suits.  Against an artificial double or 2 bid to show a single suit, responder can use lebensohl immediately, ignoring which suit was to be shown. Or, if interested in what the suit is, can pass and over the identified suit use all of lebensohl.

5)      Escaping from a penalty double – Playing weak notrumps having ways of scrambling to a better contract is essential, if only to recover a small handful of matchpoints or IMPs.  Even playing strong notrumps getting caught in a penalty double can be costly.  Here is one suggested treatment that doesn’t require much memory work.  After 1NT is doubled for penalty, a redouble is a run out to 2 either to play or to scramble to 2.  A rebid of 2 after the redouble shows both majors.  All other bids are simply what you normally play over 1NT, including Stayman, transfers, etc.  This way you can run to any suit at the two level. 

6)      Overcoming a Lead Directing Double – If the opponents double our 2 Stayman bid,

-        Pass shows exactly one club stopper.

-        Redouble shows two or more club stoppers.

-        Neither of the above actions says anything about majors.

-        2 after one of the above actions is re-Stayman.

-        Any other bid indicates no club stoppers.


Review:            Partner             RHO                You

1NT                 2                   ?

(1)      *73  AJ1084  9743 75               Bid 2, signoff.

(2)      *A7   KJ1094  42 10963           Bid 2NT followed by 3, invitational.

(3)      * A7  AQJ85  8654 64               Bid 3, game forcing.

(4)      *AQ986  86  974 872                Bid 2, signoff

                        Partner             RHO                You

1NT                 2                   ?

(5)      *1092  53  KJ10974 83             Bid 2NT followed by 3, signoff.

(6)      *82  4  AQ10 KQ109742          Bid 3, game forcing.

(7)      *AQ986  86  974 872                Bid 2, signoff

(8)      * AQ986  75  Q102 K93           Bid 3, game forcing.

(9)      *J1098  43  AQJ Q1087            Bid 3, Stayman without a stopper.

(10)  *Q1082  AJ  652 A1043            Bid 2NT followed by 3, Stayman with a heart stopper.

(11)  *A9  652  AQ9 J8432                Bid 3NT, game forcing without a heart stopper.

(12)  *AJ2  A9  Q976 J1083              Bid 2NT followed by 3NT, game force with a heart stopper.

(13)  *872  1098  KJ1094 A10          Bid 3NT, a stretch without a heart stopper.

(14)  *A972  4  J10 KQ10986           Bid 3, game forcing, opener can bid spades.

(15)  *AQ109  43  Q1095 873           Bid Double, for takeout.


[1] Mel Colchamiro. The Rule of Eight is discussed in the article Defenses to 1NT, Daily Bulletin, Spring North American Bridge Championships, Vol. 50 No. 8, Friday, March 16, 2007.

[2] A good summary of Defenses against 1NT,

[3] Mel Colchamiro. Mirror, mirror on the wall … - part 1, Bridge Bulletin, Vol. 74, No. 12, Dec. 2008.

[4] Mel Colchamiro. Mirror, mirror on the wall … - part 2, Bridge Bulletin, Vol. 75, No. 1, Jan. 2009.

[5] Mel Colchamiro. Mirror, mirror on the wall … - part 3, Bridge Bulletin, Vol. 75, No. 2, Feb. 2009.

[6] Ron Anderson. The Lebensohl Convention Complete in Contact Bridge, Barclay Bridge Supplies, Inc. 1987.