Author Topic: Formula for my league to be used with TD  (Read 596 times)

candidog

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Formula for my league to be used with TD
« on: April 05, 2011, 01:05:54 PM »
Currently I use an excel spreadsheet to my league rankings.  I posting my formula in excel below can someone convert this formula to be use with TD.  This will make me updating my tournaments quick and fast.  I appreciate if any can take the time to do this.  Let me know if you have any questions about my formula?

 

The tournament average and tournament percentage point uses the following formula. The Natural "Logarithm Rankings" system gives no advantage to simply playing more often; it gives more weight to good results, and less weight to bad results, such that one exceptionally bad result does not kill your ranking and one exceptionally good result will not boost your ranking dramatically.

Calculation details:
Where "X" is finishing place out of "N" players, each player's individual tournament result is valued at:
ln ( (N + 1) / X )
ln = "natural" base for logarithms - a universal number known as "e" = 2.718282. and "natural logarithms" are logarithms "to the base e" - that is, numbers expressed as powers of "e".

For example, with 300-player tournaments, a player finishing 1st, 300th, and 300th would rate 1.9046, just slightly better than a player finishing 45th every time, 1.9004.
Then these natural logarithms are converted back into percentiles.
To convert the natural log score back to percentile, you need to use this formula:
(1 - exp (-L) ) * 100
The variable L is the average of all the natural log score. The 'exp' means the inverse of natural log.

For example:
Log scores from 3 different tournaments: 1.5, 2.0, and 1.0.
The average of these three tournaments is 1.5.
Then plug that number into the above formula:
= (1 - exp ( -1.5 ) )* 100
= (1 - 0.22313016 ) * 100
= 77.686984


-Greg

Corey Cooper

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Re: Formula for my league to be used with TD
« Reply #1 on: April 05, 2011, 03:30:08 PM »
This is actually the default scoring method for the TD, so you don't need to do anything.  Just press the "Refresh Tourneys" button on the Stats page.  The Overall Score column should give you the correct results.

To see for yourself, press the Filters button.  Select the "default" filter (which should be the only one and already selected unless you've created your own Filters).  Press the "Tournament Scoring" button to see the individual formula.  Press the Overall Scoring button to see the cumulative formula.  They are the equivalent of the formulas you posted.