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Login: | Explaining level changesDivision 1: Lansdown A v Workout Harbourside A (Thu 28 Mar 2019)Match played between Hannah Scott (home) and Ela Sieradzan (away).Match won by Hannah Scott. Result: 15-0,15-1,15-3. Starting level for Hannah Scott: 635, level confidence: 75%. Set manually. Starting level for Ela Sieradzan: 185, level confidence: 57%. Hannah Scott to win as she is currently playing 243% better than Ela Sieradzan. Hannah Scott won all of the games and 92% of the points. This games result would be expected if she was better by around 55% or more. This points result would be expected if she was better by around 1000% (PAR scoring). These are weighted and combined to calculate that Hannah Scott played 1000% better than Ela Sieradzan in this match. Assuming that any level changes are shared between both players, for this result it looks like Hannah Scott actually played at a level of 1,137 and Ela Sieradzan at a level of 103. Without any damping, both players would need to be adjusted by 79% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 37% and 37% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Hannah Scott changes to +28% and Ela Sieradzan changes to -37%. After applying standard match damping, the adjustment for Hannah Scott becomes +14.8% and for Ela Sieradzan becomes -19%. Apply match/event weighting of 75% for 'Womens Ladies Spring 2018/2019' so the adjustment for Hannah Scott is +11.1% and for Ela Sieradzan is -13%. 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 Hannah Scott is limited to +10% and Ela Sieradzan 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. Hannah Scott: 87%, Ela Sieradzan: 75%. Reduce level confidence based on how unexpected the result is. Hannah Scott: 48%, Ela Sieradzan: 42%. A final adjustment of -0.3% 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 Hannah Scott: 695, level confidence: 48%. Final level for Ela Sieradzan: 176, level confidence: 42%. Notes
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