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Login: | Explaining level changesDivision 2: Kingsdown v Weston A (Thu 27 Nov 2014)Match played between Mandy Lewis (home) and Hannah Brown (away).Match won by Mandy Lewis. Result: 9-6,9-3,9-2:9-4,6-9,9-8,9-8:3-9,4-9,6-9:9-1,9-7,6-9,0-9,2-9:9-5,3-9,9-6,7-9,8-10. Starting level for Mandy Lewis: 469, level confidence: 72%. Set manually. Starting level for Hannah Brown: 222, level confidence: 45%. Mandy Lewis to win as she is currently playing 111% better than Hannah Brown. Mandy Lewis won all of the games and 71% 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 58% (english scoring). These are weighted and combined to calculate that Mandy Lewis played 57% better than Hannah Brown in this match. Due to the difference between the players' levels, allow for the likelihood that Mandy Lewis was taking it easy by anything up to 14%. This gives her an allowed level range for this match between 335 and 469 without affecting her level. In this case, Mandy Lewis played at level 375 and remained within her allowed range so her level will not be adjusted. On the assumption that Mandy Lewis would normally have been playing at level 404 (based on typical behaviour), Hannah Brown played better than expected and therefore gains a pre-damping level increase of 7.7%. Allowing for the difference in level between the players, the adjustments have been reduced to 0% and 5.2% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Mandy Lewis changes to 0% and Hannah Brown changes to +5.2%. After applying standard match damping, the adjustment for Mandy Lewis becomes 0% and for Hannah Brown becomes +4.1%. Apply match/event weighting of 75% for 'Womens Ladies Winter 2014/2015' so the adjustment for Mandy Lewis is 0% and for Hannah Brown is +3.1%. Increase level confidence due to one more match played. Mandy Lewis: 85%, Hannah Brown: 67%. Reduce level confidence based on how unexpected the result is. Mandy Lewis: 73%, Hannah Brown: 58%. A final adjustment of -0.3% 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 Mandy Lewis: 468, level confidence: 73%. Final level for Hannah Brown: 228, level confidence: 58%. Notes
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