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Login: | Explaining level changesDivision 1: Lansdown A v Redland Winter Lynx (Thu 20 Apr 2023)Match played between Hannah Scott (home) and Ruth Drysdale (away).Match won by Hannah Scott. Result: 15-7,15-10,15-5. Starting level for Hannah Scott: 857, level confidence: 81%. Set manually. Starting level for Ruth Drysdale: 690, level confidence: 66%. Hannah Scott to win as she is currently playing 24% better than Ruth Drysdale. Hannah Scott won all of the games and 67% 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 105% (PAR scoring). These are weighted and combined to calculate that Hannah Scott played 105% better than Ruth Drysdale 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 1,100 and Ruth Drysdale at a level of 538. Without any damping, both players would need to be adjusted by 28% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 25% and 25% 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 +20% and Ruth Drysdale changes to -25%. After applying standard match damping, the adjustment for Hannah Scott becomes +11.4% and for Ruth Drysdale becomes -14%. Apply match/event weighting of 75% for 'Womens Womans Spring 2022/2023' so the adjustment for Hannah Scott is +8.5% and for Ruth Drysdale is -9.8%. 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 Ruth Drysdale 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: 90%, Ruth Drysdale: 81%. Reduce level confidence based on how unexpected the result is. Hannah Scott: 70%, Ruth Drysdale: 63%. A final adjustment of -0.2% 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: 928, level confidence: 70%. Final level for Ruth Drysdale: 656, level confidence: 63%. Notes
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