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Login: | Explaining level changesDivision 1: Redland Winter Lynx v Lansdown A (Thu 30 Mar 2017)Match played between Ruth Drysdale (home) and Quita Colston (away).Match won by Ruth Drysdale. Result: 9-0,9-3,9-3. Starting level for Ruth Drysdale: 532, level confidence: 60%. Starting level for Quita Colston: 522, level confidence: 79%. Set manually. Ruth Drysdale to win as she is currently playing 2% better than Quita Colston. Ruth Drysdale won all of the games and 82% 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 118% (english scoring). These are weighted and combined to calculate that Ruth Drysdale played 118% better than Quita Colston in this match. Assuming that any level changes are shared between both players, for this result it looks like Ruth Drysdale actually played at a level of 778 and Quita Colston at a level of 357. Without any damping, both players would need to be adjusted by 46% 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 Ruth Drysdale changes to +46% and Quita Colston changes to -32%. After applying standard match damping, the adjustment for Ruth Drysdale becomes +22.5% and for Quita Colston becomes -17%. Apply match/event weighting of 75% for 'Womens Ladies Spring 2016/2017' so the adjustment for Ruth Drysdale is +17% and for Quita Colston is -12%. 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 Ruth Drysdale is limited to +10% and 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. Ruth Drysdale: 78%, Quita Colston: 89%. Reduce level confidence based on how unexpected the result is. Ruth Drysdale: 53%, Quita Colston: 61%. 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 Ruth Drysdale: 584, level confidence: 53%. Final level for Quita Colston: 496, level confidence: 61%. Notes
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