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Login: | Explaining level changesDivision 2: University of Bath Ladies B v Chippenham Olympiad A (Thu 09 Nov 2017)Match played between Alice O'Keeffe (home) and Lara Sherwood (away).Match won by Lara Sherwood. Result: 2-9,3-9,5-9:4-9,0-9,2-9:3-9,1-9,0-9:1-9,1-9,0-9:2-9,1-9,0-9. Starting level for Alice O'Keeffe: 100, level confidence: 45%. Starting level for Lara Sherwood: 502, level confidence: 69%. Lara Sherwood to win as she is currently playing 402% better than Alice O'Keeffe. Lara Sherwood won all of the games and 73% 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 67% (english scoring). These are weighted and combined to calculate that Lara Sherwood played 67% better than Alice O'Keeffe in this match. Due to the difference between the players' levels, allow for the likelihood that Lara Sherwood was taking it easy by anything up to 42%. This gives her an allowed level range for this match between 145 and 502 without affecting her level. In this case, Lara Sherwood played at level 220 and remained within her allowed range so her level will not be adjusted. On the assumption that Lara Sherwood would normally have been playing at level 289 (based on typical behaviour), Alice O'Keeffe played better than expected and therefore gains a pre-damping level increase of 32%. Allowing for the difference in level between the players, the adjustments have been reduced to 0% and 13% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Lara Sherwood changes to 0% and Alice O'Keeffe changes to +13%. After applying standard match damping, the adjustment for Lara Sherwood becomes 0% and for Alice O'Keeffe becomes +7.9%. Apply match/event weighting of 75% for 'Womens Ladies Winter 2017/2018' so the adjustment for Lara Sherwood is 0% and for Alice O'Keeffe is +5.9%. Increase level confidence due to one more match played. Lara Sherwood: 83%, Alice O'Keeffe: 67%. Reduce level confidence based on how unexpected the result is. Lara Sherwood: 48%, Alice O'Keeffe: 39%. A final adjustment of -1.3% 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 Alice O'Keeffe: 105, level confidence: 39%. Final level for Lara Sherwood: 494, level confidence: 48%. Notes
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