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Login: | Explaining level changesDivision 2A: Weston v Lansdown Summer A (Wed 26 Nov 2008)Match played between Julian Titchener (home) and Andy Higham (away).Match won by Julian Titchener. Result: 9-7,9-7,9-4. Starting level for Julian Titchener: 890, level confidence: 76%. Set manually. Starting level for Andy Higham: 876, level confidence: 76%. Set manually. Julian Titchener to win as he is currently playing 2% better than Andy Higham. Julian Titchener won all of the games and 60% 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 24% (english scoring). These are weighted and combined to calculate that Julian Titchener played 34% better than Andy Higham in this match. Assuming that any level changes are shared between both players, for this result it looks like Julian Titchener actually played at a level of 1,023 and Andy Higham at a level of 762. Without any damping, both players would need to be adjusted by 15% 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 Julian Titchener changes to +15% and Andy Higham changes to -15%. After applying standard match damping, the adjustment for Julian Titchener becomes +8.7% and for Andy Higham becomes -8.8%. Apply match/event weighting of 75% for 'Mixed Autumn 2008/2009' so the adjustment for Julian Titchener is +6.5% and for Andy Higham is -6.5%. 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 Andy Higham 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. Julian Titchener: 87%, Andy Higham: 87%. Reduce level confidence based on how unexpected the result is. Julian Titchener: 76%, Andy Higham: 76%. A final adjustment of +1.1% 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 Julian Titchener: 950, level confidence: 76%. Final level for Andy Higham: 851, level confidence: 76%. Notes
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