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PR/Grid rating: A snapshot correlation
Posted By: AdamStocks
Date: Tuesday, 18 August 2015, at 9:26 a.m.
One day late last year I did a snapshot data collection exercise using the PR information from the ebif.at website, and plotted them against the GridGammon ratings of the players concerned. I excluded those players with <5000 experience. I weighted the data according to the number of matches played by each of the 127 players included, and plotted the resulting 1479 datapoints in Excel. A linear trendline shows the approximate formula for relating these PRs with rating: Rating=2063.839.164*PR. Thus 1 PR = approx 39.2 Grid rating points for this dataset. (Without the weighting for #matches, the formula for 127 datapoints was Rating=2064.239.258*PR). The polynomial trendline Rating=0.147*PR^236.714*PR+2054.8 is almost congruent to the linear one. It should be noted that ebif matches tend to be longer than the typical GridGammon match. Obviously the dataset isn't huge, but was the best I could get easily. The Excel is here:
https://www.dropbox.com/s/8hivxvwwukt7zcs/EBIF%20PR%20v%20Gridgammon%20Rating.xls?dl=0

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