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Login: | Explaining level changesDivision 2: Workout Harbourside B v University of Bath Ladies A (Thu 13 Oct 2022)Match played between Helen Fay (home) and Thea Morgan (away).Match won by Thea Morgan. Result: 5-15,10-15,5-15. Starting level for Helen Fay: 222, level confidence: 53%. Starting level for Thea Morgan: 157, level confidence: 46%. Helen Fay to win as she is currently playing 41% better than Thea Morgan. Thea Morgan won all of the games and 69% 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 125% (PAR scoring). These are weighted and combined to calculate that Thea Morgan played 125% better than Helen Fay in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Thea Morgan actually played at a level of 280 and Helen Fay at a level of 124. Without any damping, both players would need to be adjusted by 78% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 63% and 63% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Thea Morgan changes to +63% and Helen Fay changes to -49%. After applying standard match damping, the adjustment for Thea Morgan becomes +29.4% and for Helen Fay becomes -24%. Apply match/event weighting of 75% for 'Womens Autumn 2022/2023' so the adjustment for Thea Morgan is +22% and for Helen Fay is -17%. 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 Thea Morgan is limited to +10% and Helen Fay 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. Thea Morgan: 68%, Helen Fay: 73%. Reduce level confidence based on how unexpected the result is. Thea Morgan: 38%, Helen Fay: 41%. A final adjustment of -0.7% 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 Helen Fay: 207, level confidence: 41%. Final level for Thea Morgan: 173, level confidence: 38%. Notes
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