Theory and Conventions


M J Bridge




The double as considered on this page is of the strong variety. This corresponds with the thought that a penalty from the opponents’ doubled contract is a desirable possibility.

Facing this strong variety of double, partner’s first instinct should be to pass unless there is a good reason not to.

Such doubles will be a standard part of the armoury when facing a weak no trump.

They may also be used against a strong no trump but in that case a degree of caution is advised - they can backfire (see below).

Alternatively you may play some other version of a double against a strong no trump.  Such bids are considered as part of the conventional method of which they form part - typically D.O.N.T. or multi-Landy.

Over time there have been a number of styles, ranging from doubling with any opening hand (say 13 points) to doubling only if you can see seven quick tricks on your opening lead.  You will not be surprised that both of these extreme styles are flawed.

A consensus is now forming, although there will be partnership variations on this ‘normal’ style.

At its simplest, in the immediate overcall position, double a weak no trump on any hand of sixteen (fifteen is also quite a common partnership agreement) or more points, and also double if you hold a hand of fourteen or fifteen points together with an attacking lead - i.e. a long suit with some solidity at the top such that you can count a likely six tricks in your hand.

Beginner and above

K J 6 4

A 8 5 3

A 2

Q T 8

Opponents open 1NT (weak).


Just fourteen points and no attacking suit.

K Q J T 6 4

A K 3


Q T 4

Opponents open 1NT (weak).

Double - the perfect hand.  Lead a spade to clear the ace, and expect to take at least seven tricks in defence.  If the opponents escape then you can bid 2, giving partner an accurate description of your hand.

K Q J T 6 4

A 8 3


Q 9 4

Opponents open 1NT (12-14).

Certainly you are likely to take your opponents down in 1NTx, but do not double.

Consider a pass if they are vulnerable.

Otherwise bid 2.


My guideline

Should I always double a weak no trump with sixteen points?

Yes - and when you have slightly less together with a long strong suit.

Too strong to double?

There are occasional situations in which your hand might be too strong to double.

The argument goes along the following lines:-

‘If you hold nineteen points and the opening bidder holds twelve then there are only nine points left in the pack.  The odds are against partner holding as many as five.  In this case he is likely to pull the double (reading you for sixteen points) for an inferior score.

Bearing this in mind you should double with sixteen to eighteen points and pass with nineteen or more.’

The argument certainly contains more than a grain of truth but the rule which goes along with it is greatly oversimplified.

It is better to grasp the principle and then decide each case on its merits.

Clearly the calculation will be affected by the range of the opponents’ no trump (for example, the calculation above would be significantly different if your opponents were playing a mini-no trump on ten to twelve points).

Equally important is a consideration of the vulnerability, particularly at pairs scoring.

The thoughts which follow are also simplified, but they provide a starting point for your decisions.

If you hold something in the region of twenty points assume that you can take your opponents down by two tricks and that you can make a part-score your way worth, say, 110, 120 or 140.  (The simplification lies in that assumption.  Feel free to modify it as you wish, along with the ensuing conclusions.)

When your opponents are vulnerable you have every hope that an undoubled penalty (say 200) will score better than your part-score (say 140). Be prepared to pass with nineteen or more points.

When your opponents are not vulnerable you should be more prepared to double.  Partner might well pull the double, but you still have hopes of scoring better in the ensuing part-score (say 110 or 140 rather than 100).

If you can see a real possibility of bidding and making a game your way, even after your partner has pulled a double, then the calculation changes.

When the opponents are not vulnerable it will in general pay to play in the game whether or not you are vulnerable.  Start by doubling with something like twenty three or more points.

With both sides vulnerable it is a close decision.  With good defence hope to take them down by three tricks.

Double first, and then bid a game if you are unable to find a subsequent penalty double.

Not vulnerable against vulnerable it will still in general pay to pass with twenty or more points, but each case should be considered on its merits.

Different no trump ranges

The above assumes that your opponents’ opening 1NT is of the 12-14 variety.

If their no trump is different then the principles above will not change but the numbers might.

Note that the suggestions which follow are a matter for partnership agreement - your agreements do not have to be the same as mine.

There is an obvious risk involved in doubling a strong no trump in the sixteen to eighteen point range with just sixteen points, and similarly when the opponents open a mini no trump of say ten to twelve points its preemptive effect will be greatly enhanced if you have to wait for sixteen points before you can double.

A simple and sensible guideline, although not my choice, is that the double should promise at least the top value of the opponents’ range, thus a double of the opponents’ 12-14 point no trump will promise at least fourteen points and a double of their 15-17 point no trump will promise at least seventeen points.

My personal preference is that:-

if their range is genuinely strong (at least fifteen points) then you should promise the top of their range;

if their no trump contains strong values but is still potentially weak (say 13-15, 14-16, or even 14-18) then double with sixteen points as against a weak no trump (their no trump is more likely to be at the bottom end of the range);

if their no trump is less than a weak no trump then your double should promise at least the top of their range but with a minimum of fourteen.

Doubling in the protective seat

You should certainly be prepared to enter the fray following an opening bid of 1NT and two passes, but you should not decrease your requirements to the same extent you might over a one of a suit opening.  The difference is that responder might well have as many as ten points, and be ready to pounce - there is no certain inference that partner must hold some values.

Many partnerships will retain the requirement of sixteen points for a double in this position.

That is just a little too safety-conscious, particularly at pairs play.

If your holding is at least as good as the top of opener’s range then the chances are that your side will hold more than half the points in the pack more than half the time.  That is all you need to justify a bid at pairs - if it works more than half the time then it is a good bid.

In other words, double in the protective seat with fourteen points (facing a 12-14 point no trump) if there is not a more obvious suit bid.

Long suit in a weaker hand

Some partnerships will agree to double on a sixteen-point hand as above, and also on a significantly weaker hand with a running suit in which you can take a likely seven quick tricks on lead.

The method is not recommended.

Better partnerships will always wriggle their way out of the 1NT doubled contract, and partner will be sorely tempted to make a (possibly) disastrous penalty double of their escape based mainly on your non-existent defensive holding.

If your opponents are vulnerable just pass, particularly at pairs.  One off may well be your best score, and if you can take them two off a score of 200 will almost always score well.

If they are not vulnerable then you might prefer to bid your suit naturally at either the two- or the three-level, with a view to making a contract your way.

K J T 4

A 5 3

A 6 4 2

Q 8

Opponents open 1NT (12-14).

Most would pass in the immediate overcall position.

After two passes you should double at pairs.  This will score well more often than not.

Passed hand

Of course, if yours is a passed hand then your double can hardly carry the same punitive message.

You can therefore redefine this bid in one way or another when this is the case.

Gates double or Gates adjunct

It is likely that this convention, or addition to other conventions, was originated by someone with the surname Gates and that an apostrophe would therefore be appropriate in its title.  As I can find no reference to the convention which contains such a nicety I have decided to omit it.

This convention can be added to any system of defence against an opening bid of 1NT which incorporates a penalty double - for example Asptro or Cappelletti.

The alternative interpretation is totally up to the partnership.

Clearly it will either fill in a missing hand-type, or add greater definition to their agreed system.

Playing Asptro in which 2 and 2 are both artificial it might well be a weak take-out at the two-level into either minor.  Partner will bid 2 which you will either pass or correct.

Similarly, playing Cappelletti, it could be used to provide a weak take-out at the two-level in clubs.

Alternatively, playing Cappelletti, it could be used to distinguish between 5-4 and 4-5 shape in the majors.

Any one of these would add to the existing method.  Just be certain that you have agreed on your partnership understanding.

J 5

A 8 4

Q J T 6 3 2

8 5

You have already passed at favourable vulnerability and RHO opens 1NT in fourth seat.

Your agreed method is Asptro, and the Gates double is played as a weak take-out into a minor.

2 would be Asptro.

Double.  Partner will bid 2 and you will correct to diamonds.

Intermediate and above

Advancer’s next bid

This page last revised 7th Mar 2019

Context - Acol bidding - overcaller - opponents opened 1NT - natural methods.

The other significant difference in the protective seat is the manner in which you deal with a long strong suit.

In the immediate overcall position you would either pass or double, hoping to lead out that suit in defence.

In the protective seat this is not an effective strategy.  It is all but certain that partner will fail to find your suit with his opening lead, after which declarer might well make his contract as your suit fails to see the light of day.

Much better to bid it at some appropriate level.

K Q J T 6 5 4

A 3

A 6 4 2

Opponents open 1NT (12-14).

In the immediate overcall position you would double and lead a spade, expecting to take at least seven tricks in defence. With two chances to establish your spade suit you might just do the same after two passes.  Change one of the aces to a collection of minor honours and you should prefer a jump to 3.

K 9 5 4

A J 8 6 4

3 2

8 5

You have already passed at favourable vulnerability and RHO opens 1NT in fourth seat.

Your agreed method is Cappelletti, and the Gates double is played as five spades and four hearts.

Bid 2 promising five hearts and four spades.