Contract Bridge
One Table Bridge
Compensation scoring

  1. Average score expectation
  2. Compensation scoring
  3. Using International Match Points (IMPs)
  4. Length points & Shortage points

    Score sheets - Calculation Tables

    Scoring - Duplicate Bridge

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COMP 1 - Average score expectation

I am sure you too have been in this situation, sitting at home with three other players playing a game of bridge.
Unfortunately this is not all that satisfying, for if you have good cards you win, and if you have bad cards you lose. There is no way you can measure your rate of success or failure on a deal.

Some players in Kharkov, Ukraine, felt the same and thought about it : "How can you eliminate the element of luck when deals are only played at one table ?"

They came up with an idea which was further developed by players in Moscow, who ran thousands of deals through a computer.
They calculated the scoring expectations with a given number of High Card Points in the Partnership hands.
The results are shown on the adjacent Table.

With the use of this Table players can measure at the end of a deal whether they have met, fallen short of or surpassed expectations. In other words you are playing against the average result of thousands of deals with the same strength.

Source : ACBL Bridge Encyclopedia, Edition 2011

The Russian analysis does not take the high cards distribution of individual deals into account.
For example on any deal, if a King sits in a hand over the Ace (of the same suit) it will most likely make a trick. However if the King sit in a hand under the Ace it will most likely be captured.
The Compensation value (shown in the Table above) is an accumulated average of all card distributions, both adverse and favourable.

Therefore the comparative result you score on each separate deal with respect to the Compensation value will be :
in part a reflection of your skill,
and in part a reflection of the high cards distribution of the deal.

Taken over a number of deals however, the card distribution factor will gradually diminish, while at the same time your skill level will come more discernable to the fore.

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COMP 2 - Compensation scoring

The computed results are presented in a Compensation Table (shown in the previous chapter) which can be used to calculate a realistic result on each deal played at one Table only.
The calculation is very easy :

  1. Add up the HCPs of Declarer and Dummy's hand

  2. Select the appropriate average score from the Compensation Table

  3. Subtract the Compensation score from the actual score achieved on the deal.
Example 1
NS Contract 3NT (Not Vul.) making 10 tricks = 430 points     Combined HCP = 27
Compensation amount for 27 HCP = 400
Calculation :   430 (actual score) - 400 (compensation amount) = +30 (adjusted score)

Example 2
NS Contract 4♥ (Vul.) making 9 tricks = -100 points     Combined HCP = 24
Compensation amount for 24 HCP = 290
Calculation :   -100 - 290 = -390     (This means that EW have scored +390)

I have designed a Score sheet which can be used to score One Table Bridge sessions. (Print out the Score sheet in "Landscape" format)

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COMP 3 - Using IMPs (International Match Points)

By using trick & bonus point scores only the result of a single deal can dominate the overall result for a whole session of play.
In regular Pairs duplicate play this is remedied by calculating Match Points, but with only one Table in play this is not possible.

In Teams and some special events scores are converted into International Match Points (IMPs), and I suggest that the use of this method is also most appropriate for converting a Compensation adjusted score into a balanced, realistic end result.
The Table provided here can be used to convert any One Table Bridge Compensation score into IMPs.

The Score sheet below shows the Compensated scores converted into their corresponding IMPs.
Note that the negative score of NS in Example 2 is recorded as a positive IMP score for EW.

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COMP 4 - Length Points & Shortage Points

It is my impression that in the computer analyses only High Card Points were considered. It is therefore debatable whether Length points (LP) or Shortage points (SP) should be included in the actual One Table Bridge compensation calculation.
But in view of the considerable positive effect a void or a singleton can have on the strength of a hand and on its boost in trick taking potential I recommend that you do consider it.

3 Shortage Points for a singleton       5 Shortage Points for a void

Suit length too can boost a hand's strength. Adding Length Points (where Shortage points are not applicable) is therefore also an option.
The important thing is to agree before the start of play, on whether or not to consistently use these minor adjustments to the HCP total.

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© 2013 Michael Furstner