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Login: | Explaining level changesDivision 1: Redland Winter Lynx v Lansdown A (Thu 07 Nov 2019)Match played between Sarah Trevelyan (home) and Quita Colston (away).Match won by Sarah Trevelyan. Result: 15-12,15-13,15-5. Starting level for Sarah Trevelyan: 615, level confidence: 83%. Set manually. Starting level for Quita Colston: 552, level confidence: 66%. Sarah Trevelyan to win as she is currently playing 11% better than Quita Colston. Sarah Trevelyan won all of the games and 60% 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 50% (PAR scoring). These are weighted and combined to calculate that Sarah Trevelyan played 52% better than Quita Colston in this match. Assuming that any level changes are shared between both players, for this result it looks like Sarah Trevelyan actually played at a level of 718 and Quita Colston at a level of 473. Without any damping, both players would need to be adjusted by 17% 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 Sarah Trevelyan changes to +12% and Quita Colston changes to -16%. After applying standard match damping, the adjustment for Sarah Trevelyan becomes +7.6% and for Quita Colston becomes -9.2%. Apply match/event weighting of 75% for 'Womens Ladies Autumn 2019/2020' so the adjustment for Sarah Trevelyan is +5.7% and for Quita Colston is -6.8%. 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 Quita Colston is limited to -5% 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. Sarah Trevelyan: 91%, Quita Colston: 81%. Reduce level confidence based on how unexpected the result is. Sarah Trevelyan: 78%, Quita Colston: 69%. A final adjustment of -0.5% 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 Sarah Trevelyan: 645, level confidence: 78%. Final level for Quita Colston: 525, level confidence: 69%. Notes
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