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Login: | Explaining level changesDivision 2: Chew Valley Winter A v Weston String Strokers (Wed 28 Sep 2016)Match played between Phil Febrey (home) and Chris Scott (away).Match won by Chris Scott. Result: 7-9,9-6,9-4,2-9,5-9. Starting level for Phil Febrey: 798, level confidence: 52%. Starting level for Chris Scott: 1,989, level confidence: 47%. Chris Scott to win as he is currently playing 149% better than Phil Febrey. Chris Scott won 60% of the games and 54% of the points. This games result would be expected if he was better by around 10%. This points result would be expected if he was better by around 9% (english scoring). These are weighted and combined to calculate that Chris Scott played 10% better than Phil Febrey in this match. Due to the difference between the players' levels, allow for the likelihood that Chris Scott was taking it easy by anything up to 19%. This gives him an allowed level range for this match between 1,253 and 1,989 without affecting his level. As Chris Scott has played below his allowed range at 1,048, his level reduction is 20% before damping. On the assumption that Chris Scott would normally have been playing at level 1,620 (based on typical behaviour), Phil Febrey played better than expected and therefore gains a pre-damping level increase of 36%. Allowing for the difference in level between the players, the adjustments have been reduced to 12% and 22% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Chris Scott changes to -12% and Phil Febrey changes to +19%. After applying standard match damping, the adjustment for Chris Scott becomes -5.7% and for Phil Febrey becomes +10.8%. Apply match/event weighting of 75% for 'Mixed Autumn 2016/2017' so the adjustment for Chris Scott is -4.2% and for Phil Febrey is +8.1%. Increase level confidence due to one more match played. Chris Scott: 68%, Phil Febrey: 72%. Reduce level confidence based on how unexpected the result is. Chris Scott: 45%, Phil Febrey: 48%. A final adjustment of -0.6% 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 Phil Febrey: 862, level confidence: 48%. Final level for Chris Scott: 1,888, level confidence: 45%. Notes
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