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Login: | Explaining level changesEmma Coughlan v Cecilia Mercieca (Fri 11 Apr 2014)Match won by Emma Coughlan. Result: 9-0,9-5,9-3.Starting level for Emma Coughlan: 1,078, level confidence: 86%. Set manually. Starting level for Cecilia Mercieca: 898, level confidence: 90%. Set manually. Emma Coughlan to win as she is currently playing 20% better than Cecilia Mercieca. Emma Coughlan won all of the games and 77% 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 86% (english scoring). These are weighted and combined to calculate that Emma Coughlan played 86% better than Cecilia Mercieca in this match. Assuming that any level changes are shared between both players, for this result it looks like Emma Coughlan actually played at a level of 1,342 and Cecilia Mercieca at a level of 721. Without any damping, both players would need to be adjusted by 24% 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 Emma Coughlan changes to +22% and Cecilia Mercieca changes to -21%. After applying standard match damping, the adjustment for Emma Coughlan becomes +11.7% and for Cecilia Mercieca becomes -12%. Apply match/event weighting of 100% for 'BLTSC Ladies Closed 2014' so the adjustment is unchanged. 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 Emma Coughlan is limited to +9.6% and Cecilia Mercieca 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. Emma Coughlan: 93%, Cecilia Mercieca: 95%. Reduce level confidence based on how unexpected the result is. Emma Coughlan: 74%, Cecilia Mercieca: 76%. A final adjustment of -0.1% 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 Emma Coughlan: 1,180, level confidence: 74%. Final level for Cecilia Mercieca: 854, level confidence: 76%. Notes
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