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Login: | Explaining level changesJames Boyack v Ceri Tibbles (Mon 20 Feb 2017)Match won by James Boyack. Result: 9-6,9-1,6-9,9-5.Starting level for James Boyack: 133, level confidence: 77%. Set manually. Starting level for Ceri Tibbles: 55, level confidence: 74%. Set manually. James Boyack to win as he is currently playing 142% better than Ceri Tibbles. James Boyack won 75% of the games and 61% 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 26% (english scoring). These are weighted and combined to calculate that James Boyack played 25% better than Ceri Tibbles in this match. Due to the difference between the players' levels, allow for the likelihood that James Boyack was taking it easy by anything up to 18%. This gives him an allowed level range for this match between 82 and 133 without affecting his level. As James Boyack has played below his allowed range at 75, his level reduction is 9% before damping. On the assumption that James Boyack would normally have been playing at level 110 (based on typical behaviour), Ceri Tibbles played better than expected and therefore gains a pre-damping level increase of 26%. Allowing for the difference in level between the players, the adjustments have been reduced to 5.7% 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 James Boyack changes to -5.5% and Ceri Tibbles changes to +16%. After applying standard match damping, the adjustment for James Boyack becomes -4.3% and for Ceri Tibbles becomes +9.3%. Apply match/event weighting of 50% for 'Kingsdown & Horfield Boxes' so the adjustment for James Boyack is -2.1% and for Ceri Tibbles is +4.7%. Increase level confidence due to one more match played. James Boyack: 88%, Ceri Tibbles: 86%. Reduce level confidence based on how unexpected the result is. James Boyack: 63%, Ceri Tibbles: 62%. A final adjustment of -1.3% 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 James Boyack: 129, level confidence: 63%. Final level for Ceri Tibbles: 57, level confidence: 62%. Notes
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