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Login: | Explaining level changesDivision 2: University of Bath Ladies B v Workout Harbourside B (Thu 30 Mar 2023)Match played between Milly Wilson (home) and Anna-Jane Singh (away).Match won by Anna-Jane Singh. Result: 8-15,9-15,9-15. Starting level for Milly Wilson: 326, level confidence: 57%. Starting level for Anna-Jane Singh: 255, level confidence: 82%. Set manually. Milly Wilson to win as she is currently playing 28% better than Anna-Jane Singh. Anna-Jane Singh won all of the games and 63% 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 73% (PAR scoring). These are weighted and combined to calculate that Anna-Jane Singh played 73% better than Milly Wilson in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Anna-Jane Singh actually played at a level of 379 and Milly Wilson at a level of 219. Without any damping, both players would need to be adjusted by 49% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 42% and 42% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Anna-Jane Singh changes to +29% and Milly Wilson changes to -42%. After applying standard match damping, the adjustment for Anna-Jane Singh becomes +15.4% and for Milly Wilson becomes -21%. Apply match/event weighting of 75% for 'Womens Womans Spring 2022/2023' so the adjustment for Anna-Jane Singh is +12% and for Milly Wilson is -15%. 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 Anna-Jane Singh is limited to +10% and Milly Wilson is limited to -5.8% 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. Anna-Jane Singh: 90%, Milly Wilson: 75%. Reduce level confidence based on how unexpected the result is. Anna-Jane Singh: 61%, Milly Wilson: 51%. A final adjustment of +6.2% 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 Milly Wilson: 308, level confidence: 51%. Final level for Anna-Jane Singh: 317, level confidence: 61%. Notes
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