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Login: | Explaining level changesAlex Williams v Belinda Wilkes (Sat 21 Jan 2023)Match won by Alex Williams. Result: 15-7,15-8,15-10.Starting level for Alex Williams: 875, level confidence: 81%. Set manually. Starting level for Belinda Wilkes: 327, level confidence: 52%. Alex Williams to win as he is currently playing 168% better than Belinda Wilkes. Alex Williams won all of the games and 64% 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 80% (PAR scoring). These are weighted and combined to calculate that Alex Williams played 80% better than Belinda Wilkes in this match. Due to the difference between the players' levels, allow for the likelihood that Alex Williams was taking it easy by anything up to 21%. This gives him an allowed level range for this match between 490 and 875 without affecting his level. In this case, Alex Williams played at level 639 and remained within his allowed range so his level will not be adjusted. On the assumption that Alex Williams would normally have been playing at level 694 (based on typical behaviour), Belinda Wilkes played better than expected and therefore gains a pre-damping level increase of 8.6%. Allowing for the difference in level between the players, including some additional protection for the better player, the adjustments have been reduced to 0% and 5.1% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Alex Williams changes to 0% and Belinda Wilkes changes to +5.1%. After applying standard match damping, the adjustment for Alex Williams becomes 0% and for Belinda Wilkes becomes +4.1%. Apply match/event weighting of 50% for 'Redland Green Boxes' so the adjustment for Alex Williams is 0% and for Belinda Wilkes is +2%. Increase level confidence due to one more match played. Alex Williams: 90%, Belinda Wilkes: 72%. Reduce level confidence based on how unexpected the result is. Alex Williams: 74%, Belinda Wilkes: 59%. 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 Alex Williams: 874, level confidence: 74%. Final level for Belinda Wilkes: 333, level confidence: 59%. Notes
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