Duplicate Bridge Percentage Scoring
How to work out the percentage scores in duplicate bridge
If you take part in duplicate bridge competitions, either at a club or online, you will find each hand you play is awarded a percentage score. This isn’t directly related to the number of points you scored, but tells you how well you did in comparison with the other people who played the same hand.
It isn’t hard to work out the percentages.
* First, deduct one from the number of pairs playing the hand.
– for example: if the hand was played 7 times deduct one to give 6. If the hand was played 15 times, deduct 1 to give 14
* Next award each pair points according to their position on the results table. Starting with the number you worked about above and decreasing by one for each pair. The bottom pair receives 0 points.
– For example: In the hand with 7 players, the top scoring pair would receive 6 points, the next pair 5 points, then 4 points, 3 points, 2 points and 1 point. The bottom pair receiving 0 points
* If more than one pair achieve the same score then the points are added up and divided by the number of players.
– For example: 1 pair scored 650 points, 3 pairs scored 300 points, 2 pairs scored 200 points, 1 pair scored -200 points.
| The top pair are awarded 6 points.
| The next three pairs are awarded 5+4+3 points (the next 3 places) and that is divided by the number of pairs. So (5+4+3)/3 = 4 points
| The next two pairs are awarded 2 + 1 points divided between them. So (2+1)/2 = 1.5 points each
| The bottom pair receive 0 points
* Once the points have been awarded these are converted to percentages. This is easily done by multiplying the number of points awarded to a pair by 100 and then dividing by the number of participants minus one.
– For example. The pair who were awarded 6 points scored 6 x 100/6 = 100%
– The pairs who were awarded 4 points scored 4 x 100/6 = 66.66%
– The pairs who were awarded 1.5 points scored 1.5 x 100 / 6 = 25%
– The pair who came last were awarded 0%
Here are some real examples from games I have played on bridgebase.com. I’m playing South and my results are the ones highlighted.
In this example there were 10 playing pairs. We are playing NS.
We start by subtracting one from the number of players to give us 9.
There are 9, 8, 7 ……. 1, 0 points to be awarded.
The top player received 9 points, the next 8 points. Then 6 players each had the same score, so received (7+6+5+4+3+2)/6 points, ie 27/6 = 4.5 points. The final 2 pairs received (1+0)/2 ie 0.5 points.
The top player percentage was 9×100/9 = 100%
The second player’s percentage was 8×100/9 = 88.9%
The next 6 players received 4.5×100/9 = 50%
The final two players received 0.5 x100/9 = 5.6%
In this example the game was played 14 times. So the number of points awarded runs from 13 to 0.
The first pair received 13 points.
The next 8 players received (12+11+10+9+8+7+6+5)/8 = 8.5 points
The next player received 4 points
The next 3 points
The next 2 players received (2+1)/2 = 1.5 points
The final player received 0 points.
So their respective percentages are:
Player 1 = 13*100/13 = 100%
Players 2 through 9 = 8.5*100/13 = 65.4%
Player 10 = 4*100/13 = 30.8%
Player 11 = 3*100/13 = 23.1%
Player 12 & 13 = 1.5*100/13 = 11.5%
Player 14 = 0%
Now that you know how the percentage scores are worked out, join No Fear Bridge to work on improving your bridge bidding and play. In no time your average percentages will rise and you will see how your play is improving.
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william r. smith
June 25, 2014 @ 4:07 am
Nicely written article. I was always a little unsure of exactly these percentages were computed. Thanks for taking the time to instruct!