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Login: | Explaining level changesDivision 2: Kingsdown v University of Bristol Chicken Dinners (Thu 21 Nov 2024)Match played between Kathryn Atherton (home) and Zara 'Fresher' Long (away).Match won by Kathryn Atherton. Result: 15-11,15-12,15-12. Starting level for Kathryn Atherton: 139, level confidence: 78%. Set manually. Starting level for Zara 'Fresher' Long: 151, level confidence: 59%. Zara 'Fresher' Long to win as she is currently playing 9% better than Kathryn Atherton. Kathryn Atherton won all of the games and 56% 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 29% (PAR scoring). These are weighted and combined to calculate that Kathryn Atherton played 37% better than Zara 'Fresher' Long in this match. Assuming that any level changes are shared between both players, for this result it looks like Kathryn Atherton actually played at a level of 170 and Zara 'Fresher' Long at a level of 124. Without any damping, both players would need to be adjusted by 22% to match this result. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Kathryn Atherton changes to +16% and Zara 'Fresher' Long changes to -21%. After applying standard match damping, the adjustment for Kathryn Atherton becomes +9.2% and for Zara 'Fresher' Long becomes -12%. Apply match/event weighting of 75% for 'Womens Womans Autumn 2024/2025' so the adjustment for Kathryn Atherton is +6.9% and for Zara 'Fresher' Long is -8.6%. 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 Zara 'Fresher' Long is limited to -7.8% 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. Kathryn Atherton: 88%, Zara 'Fresher' Long: 77%. Reduce level confidence based on how unexpected the result is. Kathryn Atherton: 72%, Zara 'Fresher' Long: 63%. A final adjustment of +2.1% 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 Kathryn Atherton: 150, level confidence: 72%. Final level for Zara 'Fresher' Long: 145, level confidence: 63%. Notes
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