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Login: | Explaining level changesPremier A: Lansdown 1 v Thornbury A (Wed 31 Jan 2018)Match played between Andy Ewings (home) and Callum Davidson (away).Match won by Callum Davidson. Result: 4-11,4-11,6-11. Starting level for Andy Ewings: 5,317, level confidence: 50%. Starting level for Callum Davidson: 7,973, level confidence: 66%. Callum Davidson to win as he is currently playing 50% better than Andy Ewings. Callum Davidson won all of the games and 70% of the points. This games result would be expected if he was better by around 55% or more. This points result would be expected if he was better by around 136% (PAR scoring). These are weighted and combined to calculate that Callum Davidson played 136% better than Andy Ewings in this match. Assuming that any level changes are shared between both players, for this result it looks like Callum Davidson actually played at a level of 9,996 and Andy Ewings at a level of 4,241. Without any damping, both players would need to be adjusted by 25% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 20% and 20% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Callum Davidson changes to +15% and Andy Ewings changes to -20%. After applying standard match damping, the adjustment for Callum Davidson becomes +4.7% and for Andy Ewings becomes -6.4%. Given Callum Davidson's level and the type of match played, an additional damping of 11% has been applied to his level change. Given Andy Ewings's level and the type of match played, an additional damping of 1.4% has been applied to his level change. Apply match/event weighting of 75% for 'Mixed Spring 2017/2018' so the adjustment for Callum Davidson is +3.2% and for Andy Ewings is -4.7%. Increase level confidence due to one more match played. Callum Davidson: 81%, Andy Ewings: 71%. Reduce level confidence based on how unexpected the result is. Callum Davidson: 65%, Andy Ewings: 57%. A final adjustment of +1.4% 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 Andy Ewings: 5,205, level confidence: 57%. Final level for Callum Davidson: 8,254, level confidence: 65%. Notes
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