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Login: | Explaining level changesDivision 2: University of Bath Ladies B v University of Bristol Beasts (Thu 10 Mar 2022)Match played between Lily Jackson (home) and Annabel Roest (away).Match won by Lily Jackson. Result: 15-5,12-15,15-9,15-13:15-7,15-4,16-14:15-10,15-12,7-15,14-16,12-15:15-9,15-11,15-2. Starting level for Lily Jackson: 232, level confidence: 73%. Set manually. Starting level for Annabel Roest: 84, level confidence: 49%. Lily Jackson to win as she is currently playing 176% better than Annabel Roest. Lily Jackson won 75% of the games and 58% of the points. This games result would be expected if she was better by around 25%. This points result would be expected if she was better by around 36% (PAR scoring). These are weighted and combined to calculate that Lily Jackson played 29% better than Annabel Roest in this match. Due to the difference between the players' levels, allow for the likelihood that Lily Jackson was taking it easy by anything up to 22%. This gives her an allowed level range for this match between 134 and 232 without affecting her level. As Lily Jackson has played below her allowed range at 120, her level reduction is 11% before damping. On the assumption that Lily Jackson would normally have been playing at level 182 (based on typical behaviour), Annabel Roest played better than expected and therefore gains a pre-damping level increase of 30%. Allowing for the difference in level between the players, the adjustments have been reduced to 6.6% and 17% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Lily Jackson changes to -4.3% and Annabel Roest changes to +17%. After applying standard match damping, the adjustment for Lily Jackson becomes -3.7% and for Annabel Roest becomes +9.7%. Apply match/event weighting of 75% for 'Womens Ladies Spring 2021/2022' so the adjustment for Lily Jackson is -2.8% and for Annabel Roest is +7.3%. Increase level confidence due to one more match played. Lily Jackson: 86%, Annabel Roest: 70%. Reduce level confidence based on how unexpected the result is. Lily Jackson: 58%, Annabel Roest: 48%. 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 Lily Jackson: 227, level confidence: 58%. Final level for Annabel Roest: 89, level confidence: 48%. Notes
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