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Login: | Explaining level changesPremier A: Redwood Phoenix v County Ground A (Wed 28 Mar 2007)Match played between Peter Creed (home) and Simon Roach (away).Match won by Peter Creed. Result: 5-9,9-6,9-0,9-1. Starting level for Peter Creed: 6,491, level confidence: 74%. Set manually. Starting level for Simon Roach: 2,437, level confidence: 84%. Set manually. Peter Creed to win as he is currently playing 166% better than Simon Roach. Peter Creed won 75% of the games and 67% of the points. This games result would be expected if he was better by around 25%. This points result would be expected if he was better by around 44% (english scoring). These are weighted and combined to calculate that Peter Creed played 31% better than Simon Roach in this match. Due to the difference between the players' levels, allow for the likelihood that Peter Creed was taking it easy by anything up to 21%. This gives him an allowed level range for this match between 3,864 and 6,491 without affecting his level. As Peter Creed has played below his allowed range at 3,516, his level reduction is 9.9% before damping. On the assumption that Peter Creed would normally have been playing at level 5,155 (based on typical behaviour), Simon Roach played better than expected and therefore gains a pre-damping level increase of 27%. Allowing for the difference in level between the players, the adjustments have been reduced to 6% and 16% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Peter Creed changes to -6% and Simon Roach changes to +14%. After applying standard match damping, the adjustment for Peter Creed becomes -2.5% and for Simon Roach becomes +5.9%. Given Peter Creed's level and the type of match played, an additional damping of 6% has been applied to his level change. Looks like he wasn't taking the match too seriously... Apply match/event weighting of 75% for 'Mixed Spring 2007' so the adjustment for Peter Creed is -1.7% and for Simon Roach is +4.5%. Increase level confidence due to one more match played. Peter Creed: 86%, Simon Roach: 91%. Reduce level confidence based on how unexpected the result is. Peter Creed: 60%, Simon Roach: 64%. A final adjustment of -0.1% has been made to both players as part of the automatic calibration that is performed after each match. All players in this pool will have been adjusted equally in order to remain equivalent to other player pools. Final level for Peter Creed: 6,371, level confidence: 60%. Final level for Simon Roach: 2,542, level confidence: 64%. Notes
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