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Login: | Explaining level changesDivision 3B: Gordano B v Colston Imperials A (Wed 25 Jan 2012)Match played between Steve Gale (home) and Andy Davis (away).Match won by Steve Gale. Result: 9-1,9-5,9-3:9-3,9-7,9-2:9-4,9-6,9-2:9-5,9-7,9-1:9-5,2-9,8-10,9-1,9-2. Starting level for Steve Gale: 1,050, level confidence: 76%. Set manually. Starting level for Andy Davis: 864, level confidence: 84%. Set manually. Steve Gale to win as he is currently playing 22% better than Andy Davis. Steve Gale won all of the games and 75% 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 76% (english scoring). These are weighted and combined to calculate that Steve Gale played 76% better than Andy Davis in this match. Assuming that any level changes are shared between both players, for this result it looks like Steve Gale actually played at a level of 1,264 and Andy Davis at a level of 718. Without any damping, both players would need to be adjusted by 20% 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 Steve Gale changes to +18% and Andy Davis changes to -16%. After applying standard match damping, the adjustment for Steve Gale becomes +10.2% and for Andy Davis becomes -9.5%. Apply match/event weighting of 75% for 'Mixed Spring 2012' so the adjustment for Steve Gale is +7.6% and for Andy Davis is -7%. 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 Andy Davis 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. Steve Gale: 87%, Andy Davis: 91%. Reduce level confidence based on how unexpected the result is. Steve Gale: 72%, Andy Davis: 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 Steve Gale: 1,128, level confidence: 72%. Final level for Andy Davis: 822, level confidence: 76%. Notes
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