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Login: | Explaining level changesDivision 1: Lansdown A v Weston A (Thu 28 Nov 2019)Match played between Pippa Green (home) and Eunice Bond (away).Match won by Pippa Green. Result: 15-6,15-4,15-11:15-10,15-10,15-5:15-5,15-7,15-8:15-8,15-8,15-11. Starting level for Pippa Green: 1,559, level confidence: 77%. Set manually. Starting level for Eunice Bond: 1,165, level confidence: 78%. Set manually. Pippa Green to win as she is currently playing 34% better than Eunice Bond. Pippa Green won all of the games and 68% of the points. This games result would be expected if she was better by around 55% or more. This points result would be expected if she was better by around 114% (PAR scoring). These are weighted and combined to calculate that Pippa Green played 114% better than Eunice Bond in this match. Assuming that any level changes are shared between both players, for this result it looks like Pippa Green actually played at a level of 1,973 and Eunice Bond at a level of 921. Without any damping, both players would need to be adjusted by 27% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 23% and 23% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Pippa Green changes to +23% and Eunice Bond changes to -22%. After applying standard match damping, the adjustment for Pippa Green becomes +10.3% and for Eunice Bond becomes -11%. Apply match/event weighting of 75% for 'Womens Ladies Autumn 2019/2020' so the adjustment for Pippa Green is +7.7% and for Eunice Bond is -8.3%. 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 Eunice Bond 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. Pippa Green: 88%, Eunice Bond: 88%. Reduce level confidence based on how unexpected the result is. Pippa Green: 69%, Eunice Bond: 70%. A final adjustment of -1.7% 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 Pippa Green: 1,642, level confidence: 69%. Final level for Eunice Bond: 1,098, level confidence: 70%. Notes
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