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Login: | Explaining level changesDivision 3: Kingsdown B v David Lloyd A (Thu 27 Feb 2014)Match played between Wij Wight (home) and Maryann Neudegg (away).Match won by Wij Wight. Result: 9-4,9-6,6-9,4-9,9-7. Starting level for Wij Wight: 199, level confidence: 63%. Starting level for Maryann Neudegg: 278, level confidence: 50%. Maryann Neudegg to win as she is currently playing 40% better than Wij Wight. Wij Wight won 60% of the games and 51% of the points. This games result would be expected if she was better by around 10%. This points result would be expected if she was better by around 2% (english scoring). These are weighted and combined to calculate that Wij Wight played 8% better than Maryann Neudegg in this match. Assuming that any level changes are shared between both players, for this result it looks like Wij Wight actually played at a level of 244 and Maryann Neudegg at a level of 226. Without any damping, both players would need to be adjusted by 23% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 19% and 19% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Wij Wight changes to +15% and Maryann Neudegg changes to -19%. After applying standard match damping, the adjustment for Wij Wight becomes +8.9% and for Maryann Neudegg becomes -10.8%. Apply match/event weighting of 75% for 'Womens Women's Spring 2013/2014' so the adjustment for Wij Wight is +6.7% and for Maryann Neudegg is -7.9%. 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 -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. Wij Wight: 79%, Maryann Neudegg: 70%. Reduce level confidence based on how unexpected the result is. Wij Wight: 64%, Maryann Neudegg: 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 Wij Wight: 212, level confidence: 64%. Final level for Maryann Neudegg: 264, level confidence: 57%. Notes
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