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Login: | Explaining level changesDivision 2: University of Bristol Llamas v Kingsdown (Thu 29 Jan 2015)Match played between Freya Bell (home) and Wij Wight (away).Match won by Wij Wight. Result: 5-9,2-9,9-4,8-10. Starting level for Freya Bell: 113, level confidence: 39%. Starting level for Wij Wight: 230, level confidence: 52%. Wij Wight to win as she is currently playing 104% better than Freya Bell. Wij Wight won 75% of the games and 57% of the points. This games result would be expected if she was better by around 25%. This points result would be expected if she was better by around 16% (english scoring). These are weighted and combined to calculate that Wij Wight played 22% better than Freya Bell in this match. Due to the difference between the players' levels, allow for the likelihood that Wij Wight was taking it easy by anything up to 13%. This gives her an allowed level range for this match between 169 and 230 without affecting her level. As Wij Wight has played below her allowed range at 153, her level reduction is 10.6% before damping. On the assumption that Wij Wight would normally have been playing at level 200 (based on typical behaviour), Freya Bell played better than expected and therefore gains a pre-damping level increase of 21%. Allowing for the difference in level between the players, the adjustments have been reduced to 7.3% and 14% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Wij Wight changes to -5.4% and Freya Bell changes to +14%. After applying standard match damping, the adjustment for Wij Wight becomes -4.2% and for Freya Bell becomes +8.4%. Apply match/event weighting of 75% for 'Womens Ladies Spring 2016 2014/2015' so the adjustment for Wij Wight is -3.1% and for Freya Bell is +6.3%. Increase level confidence due to one more match played. Wij Wight: 72%, Freya Bell: 62%. Reduce level confidence based on how unexpected the result is. Wij Wight: 56%, Freya Bell: 48%. 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 Freya Bell: 119, level confidence: 48%. Final level for Wij Wight: 224, level confidence: 56%. Notes
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