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Login: | Explaining level changesDivision 2: Thornbury B v Redwood Phoenix (Wed 23 Mar 2022)Match played between Nigel Ball (home) and Ben Swift (away).Match won by Ben Swift. Result: 4-15,7-15,11-15. Starting level for Nigel Ball: 1,332, level confidence: 52%. Starting level for Ben Swift: 1,920, level confidence: 81%. Set manually. Ben Swift to win as he is currently playing 44% better than Nigel Ball. Ben Swift won all of the games and 67% 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 105% (PAR scoring). These are weighted and combined to calculate that Ben Swift played 105% better than Nigel Ball in this match. Assuming that any level changes are shared between both players, for this result it looks like Ben Swift actually played at a level of 2,287 and Nigel Ball at a level of 1,118. Without any damping, both players would need to be adjusted by 19% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 16% 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 Ben Swift changes to +10.1% and Nigel Ball changes to -16%. After applying standard match damping, the adjustment for Ben Swift becomes +5% and for Nigel Ball becomes -8.2%. Apply match/event weighting of 75% for 'Mixed Spring 2021/2022' so the adjustment for Ben Swift is +3.8% and for Nigel Ball is -6%. Apply limits to the amount of change for a single match which are based on player level, level confidence and time since last match so that Nigel Ball is limited to -5% level change. In general a player's level won't go up by more than 10% or drop more than 5% if they've played in the last 7 days but those limits are relaxed if their previous match was further back. Increase level confidence due to one more match played. Ben Swift: 90%, Nigel Ball: 72%. Reduce level confidence based on how unexpected the result is. Ben Swift: 75%, Nigel Ball: 61%. A final adjustment of +0.8% 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 Nigel Ball: 1,292, level confidence: 61%. Final level for Ben Swift: 1,989, level confidence: 75%. Notes
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