Source: http://www.pikier.com
Chaos and primitivism reign in the area of doubling. The meanings of doubles are defined in far too simplistic manner compared with the variety of situations we face in the bridge life. Thus, we loose many opportunities to penalize opponents or to facilitate our own bidding by means of doubling. Moreover, it frequently happens that a double is completely differently understood by both partners even when the situation seems perfectly clear:
International Popular Bridge Monthly; August 1986 Problem 5
| West | North | East | South |
| Pass | Pass | 1 |
1 |
| Pass | Pass | 2 |
Pass |
| Pass | Doblo | Pass | ? |
Your hand: A Q x x x 
Q J x Q J 
x x x
(a) What would you bid now ?
(b) You are playing with a strange partner; Would you have alerted the double ?
Landy: Pass. The double is for penalty.
Hamilton: 2. The double is for take out.
Soloway: Pass. Partner is weak in Diamonds.
Zia: 2. North cannot have a hand to double for penalty.
Forrester: I do not alert. How can I alert with no idea what partner has.
Codge: I alert since I cannot lose whereas not alerting may often prove to be costly.
The lack of unanimity among such eminent experts is striking !
The simplistic proposition that a double is either for penalty (forcing to pass) or for take out (forcing to bid) and nothing in between, is too rigid, absurd, simplistic and puerile. Bridge is just too subtle a game for such a proposition to be tenable, as most players will admit and as justifiably proven below.
Like any other bid a double is a proposition which may be accepted or not by responder depending on circumstances. What is therefore required is a general theory and system of natural doubles which can be understood by all players and applied with reasoable confidence like hand valuation. The system will be called SAND, which stands for:
STANDARD ALGORITHM of NATURAL DOUBLING
SAND is a system intended to cater for all types of doubles, natural and conventional. It makes it always obvious with what type of hand the double was made and with what hand and when to accept or take out a double.
The fundamental character of any given bid can be defined as the suggestions it contains as to further course of the auction. Extending this to doubles, we easily arrive to the conclusion that:
The most important attribute of a double is its «PENALITY”
ie the power with which the double expresses doubler’s will to play the contract doubled, or – in other words – his readiness to penalize the opponents, or – in other words – doubler’s degree of inclination to penalize.
The word “Penality” seems best fitting and means ‘the ability to penalize’ as against ‘penalty’ which has a much more static property. The idea was to use one single word; ‘Penalty Range’ would also fit the bill but was rejected for that reason.
How is the penality measured ?
As penality increases it becomes much more profitable to penalize the opponents and accept the double, and as it decreases the opposite applies, with cases in betweeen. depending on hands. For convenience we shall measure penality by a percentage, as shown in the table below:
| Penalty | Suggestions to partner | Colloquial description of the double |
| 100% | Pass! (ie accept the double) | Penalty |
| 75% | Rather Pass! | Semi–penalty, penalty–oriented |
| 50% | Choose! (at your choice) | Optional (competitive? cooperative?) |
| 25% | Rather bid! | Semi–takeout, takeout–oriented |
| 0% | Bid ! (ie takeout the double) | Take out |
Penality < 0% or > 100% may occur !
What does the doubler have ?
Knowing the penality of the partner’s double allows us to picture his actual hand pretty well:
„Tell me the penality and I will be able to tell with what kind of hand you doubled. All the better too, the greater my experience and knowledge.” (a certain minimum is assumed)
The relationship between the penality of a double and the kind of hand the doubler has is, approximately, as follows:
| · | The greater the penality, the greater the length/strength in the doubled suit – and the smaller the length/strength in other suits (and, especially, in our suits). |
| · | For average penality (50%) those values (length/strength) are average. |
| · | The hand should contain some surplus values, making it feasible to take some action. |
| · | Shortage of distributional defensive values can be made up by possession of surplus honor strength. |
What does the penality of a hand mean ?
The notion is analogous to the penality of the double, and may be defined as below:
The penality of your hand = P if… holding this hand in a given doubling situation you would like the double to have the penality = P
Consider this sequence
1 1 ?
The penality of South hand may vary:
| –25% | 0% | 25% | 50% | 75% | 100% | 125% | 150% |
| KQJxx | Qxxx | Axxx | Qxx | Qxx | Qxx | Jxx | xxx |
| – | x | Qx | KJxx | KJxxx | KJ9xxx | KJ9xxxx | KQ98xxx |
| Kxx | KJxx | Kxxx | Axx | Axx | Ax | Ax | Axx |
| Axxxx | Axxx | Axx | xxx | xx | xx | x | – |
Obviously, with any of those holdings – with the penality P – South would be satisfied most if by prior agreement with partner (or common sense) his double in that sequence had the penality equaling P. Ufortunately, for obvious reasons this is not possible.
Continuara….