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Login: | Explaining level changesDivision 2: Lansdown 3 v Thornbury C (Wed 01 Nov 2017)Match played between Julian Moore (home) and Vivi B (away).Match won by Vivi B. Result: 9-7,9-2,2-9,5-9,4-9. Starting level for Julian Moore: 2,004, level confidence: 59%. Starting level for Vivi B: 1,514, level confidence: 72%. Set manually. Julian Moore to win as he is currently playing 32% better than Vivi B. Vivi B won 60% of the games and 55% of the points. This games result would be expected if he was better by around 10%. This points result would be expected if he was better by around 11% (english scoring). These are weighted and combined to calculate that Vivi B played 10% better than Julian Moore in this match. Assuming that any level changes are shared between both players, for this result it looks like Vivi B actually played at a level of 1,829 and Julian Moore at a level of 1,659. Without any damping, both players would need to be adjusted by 21% 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 Vivi B changes to +15% and Julian Moore changes to -18%. After applying standard match damping, the adjustment for Vivi B becomes +7.3% and for Julian Moore becomes -7.8%. Apply match/event weighting of 75% for 'Mixed Autumn 2017/2018' so the adjustment for Vivi B is +5.5% and for Julian Moore is -5.7%. 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 Julian Moore 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. Vivi B: 85%, Julian Moore: 77%. Reduce level confidence based on how unexpected the result is. Vivi B: 70%, Julian Moore: 64%. A final adjustment of +0.4% 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 Moore: 1,923, level confidence: 64%. Final level for Vivi B: 1,598, level confidence: 70%. Notes
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