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Login: | Explaining level changesDivision 1: Thornbury v Hutton Moor (Thu 14 May 2009)Match played between Maryann Neudegg (home) and Gemma Ballands (away).Match won by Maryann Neudegg. Result: 9-1,9-0,9-1. Starting level for Maryann Neudegg: 179, level confidence: 81%. Set manually. Starting level for Gemma Ballands: 135, level confidence: 58%. Maryann Neudegg to win as she is currently playing 33% better than Gemma Ballands. Maryann Neudegg won all of the games and 93% 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 278% (english scoring). These are weighted and combined to calculate that Maryann Neudegg played 278% better than Gemma Ballands in this match. Assuming that any level changes are shared between both players, for this result it looks like Maryann Neudegg actually played at a level of 302 and Gemma Ballands at a level of 80. Without any damping, both players would need to be adjusted by 69% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 58% and 58% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Maryann Neudegg changes to +42% and Gemma Ballands changes to -58%. After applying standard match damping, the adjustment for Maryann Neudegg becomes +20.8% and for Gemma Ballands becomes -27%. Apply match/event weighting of 65% for 'Womens Women's Summer 2008/2009' so the adjustment for Maryann Neudegg is +14% and for Gemma Ballands is -16%. 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 Maryann Neudegg is limited to +10% and Gemma Ballands 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. Maryann Neudegg: 90%, Gemma Ballands: 76%. Reduce level confidence based on how unexpected the result is. Maryann Neudegg: 53%, Gemma Ballands: 45%. A final adjustment of -0.4% 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 Maryann Neudegg: 197, level confidence: 53%. Final level for Gemma Ballands: 128, level confidence: 45%. Notes
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