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Login: | Explaining level changesDivision 1: Lansdown A v University of Bath Ladies A (Thu 11 Nov 2021)Match played between Hannah Scott (home) and Elizabeth Mamchits (away).Match won by Hannah Scott. Result: 15-13,15-13,16-14. Starting level for Hannah Scott: 752, level confidence: 83%. Set manually. Starting level for Elizabeth Mamchits: 321, level confidence: 58%. Hannah Scott to win as she is currently playing 134% better than Elizabeth Mamchits. Hannah Scott won all of the games and 53% 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 15% (PAR scoring). These are weighted and combined to calculate that Hannah Scott played 28% better than Elizabeth Mamchits in this match. Due to the difference between the players' levels, allow for the likelihood that Hannah Scott was taking it easy by anything up to 17%. This gives her an allowed level range for this match between 498 and 752 without affecting her level. As Hannah Scott has played below her allowed range at 453, her level reduction is 10% before damping. On the assumption that Hannah Scott would normally have been playing at level 626 (based on typical behaviour), Elizabeth Mamchits played better than expected and therefore gains a pre-damping level increase of 23%. Allowing for the difference in level between the players, the adjustments have been reduced to 6.4% and 15% 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 -4.5% and Elizabeth Mamchits changes to +15%. After applying standard match damping, the adjustment for Hannah Scott becomes -3.8% and for Elizabeth Mamchits becomes +8.7%. Apply match/event weighting of 75% for 'Womens Ladies Autumn 2021/2022' so the adjustment for Hannah Scott is -2.8% and for Elizabeth Mamchits is +6.5%. Increase level confidence due to one more match played. Hannah Scott: 91%, Elizabeth Mamchits: 76%. Reduce level confidence based on how unexpected the result is. Hannah Scott: 67%, Elizabeth Mamchits: 57%. 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: 742, level confidence: 67%. Final level for Elizabeth Mamchits: 339, level confidence: 57%. Notes
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