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Login: | Explaining level changesDivision 4A: Weston v University of Bath 3 (Wed 08 Feb 2012)Match played between Mike La Band (home) and Alex Matthews (away).Match won by Mike La Band. Result: 9-6,9-2,9-0. Starting level for Mike La Band: 732, level confidence: 54%. Starting level for Alex Matthews: 569, level confidence: 55%. Mike La Band to win as he is currently playing 29% better than Alex Matthews. Mike La Band won all of the games and 77% 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 86% (english scoring). These are weighted and combined to calculate that Mike La Band played 86% better than Alex Matthews in this match. Assuming that any level changes are shared between both players, for this result it looks like Mike La Band actually played at a level of 880 and Alex Matthews at a level of 473. Without any damping, both players would need to be adjusted by 20% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 18% and 18% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Mike La Band changes to +18% and Alex Matthews changes to -17%. After applying standard match damping, the adjustment for Mike La Band becomes +10.1% and for Alex Matthews becomes -10%. Apply match/event weighting of 75% for 'Mixed Spring 2012' so the adjustment for Mike La Band is +7.6% and for Alex Matthews is -7.3%. 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 Alex Matthews 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. Mike La Band: 73%, Alex Matthews: 74%. Reduce level confidence based on how unexpected the result is. Mike La Band: 61%, Alex Matthews: 62%. 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 Mike La Band: 786, level confidence: 61%. Final level for Alex Matthews: 541, level confidence: 62%. Notes
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