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Login: | Explaining level changesTim O'Leary v Alisdair Wriglesworth (Thu 10 Nov 2016)Match won by Alisdair Wriglesworth. Result: 9-7,9-6,8-10,3-9.Starting level for Tim O'Leary: 869, level confidence: 77%. Set manually. Starting level for Alisdair Wriglesworth: 1,727, level confidence: 70%. Set manually. Alisdair Wriglesworth to win as he is currently playing 99% better than Tim O'Leary. Alisdair Wriglesworth won 50% of the games and 52% of the points. This games result would be expected if he was better by around 0%. This points result would be expected if he was better by around 4% (english scoring). These are weighted and combined to calculate that Alisdair Wriglesworth played 2% better than Tim O'Leary in this match. Due to the difference between the players' levels, allow for the likelihood that Alisdair Wriglesworth was taking it easy by anything up to 12%. This gives him an allowed level range for this match between 1,250 and 1,727 without affecting his level. As Alisdair Wriglesworth has played below his allowed range at 1,051, his level reduction is 19% before damping. On the assumption that Alisdair Wriglesworth would normally have been playing at level 1,518 (based on typical behaviour), Tim O'Leary played better than expected and therefore gains a pre-damping level increase of 31%. Allowing for the difference in level between the players, the adjustments have been reduced to 13% and 21% respectively. As this is a best of 3 match rather than best of 5, these adjustments have been reduced to 9.7% and 15% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Alisdair Wriglesworth changes to -9.7% and Tim O'Leary changes to +14%. After applying standard match damping, the adjustment for Alisdair Wriglesworth becomes -5.1% and for Tim O'Leary becomes +8.4%. Apply match/event weighting of 50% for 'Redland Green Boxes' so the adjustment for Alisdair Wriglesworth is -2.5% and for Tim O'Leary is +4.2%. Increase level confidence due to one more match played. Alisdair Wriglesworth: 84%, Tim O'Leary: 88%. Reduce level confidence based on how unexpected the result is. Alisdair Wriglesworth: 60%, Tim O'Leary: 63%. A final adjustment of +0.9% 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 Tim O'Leary: 921, level confidence: 63%. Final level for Alisdair Wriglesworth: 1,686, level confidence: 60%. Notes
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