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Login: | Explaining level changesDivision 1: Westbury David Lloyd A v Chew Valley Winter A (Wed 24 Feb 2016)Match played between Kirk Woodward (home) and Mark Simmons (away).Match won by Kirk Woodward. Result: 9-4,9-3,9-0. Starting level for Kirk Woodward: 2,052, level confidence: 82%. Set manually. Starting level for Mark Simmons: 1,688, level confidence: 86%. Set manually. Kirk Woodward to win as he is currently playing 22% better than Mark Simmons. Kirk Woodward won all of the games and 79% of the points. This games result would be expected if he was better by around 55% or more. This points result would be expected if he was better by around 97% (english scoring). These are weighted and combined to calculate that Kirk Woodward played 97% better than Mark Simmons in this match. Assuming that any level changes are shared between both players, for this result it looks like Kirk Woodward actually played at a level of 2,612 and Mark Simmons at a level of 1,326. Without any damping, both players would need to be adjusted by 27% 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 Kirk Woodward changes to +24% and Mark Simmons changes to -23%. After applying standard match damping, the adjustment for Kirk Woodward becomes +9.9% and for Mark Simmons becomes -10.3%. Apply match/event weighting of 75% for 'Mixed Spring 2015/2016' so the adjustment for Kirk Woodward is +7.4% and for Mark Simmons is -7.5%. 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 Mark Simmons 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. Kirk Woodward: 91%, Mark Simmons: 92%. Reduce level confidence based on how unexpected the result is. Kirk Woodward: 71%, Mark Simmons: 73%. 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 Kirk Woodward: 2,203, level confidence: 71%. Final level for Mark Simmons: 1,605, level confidence: 73%. Notes
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