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Login: | Explaining level changesDivision 1: Redland Winter Lynx v Lansdown A (Thu 15 Feb 2018)Match played between Alice Clark (home) and Charlotte Weldrake (away).Match won by Alice Clark. Result: 9-3,9-1,9-7. Starting level for Alice Clark: 993, level confidence: 79%. Set manually. Starting level for Charlotte Weldrake: 911, level confidence: 75%. Set manually. Alice Clark to win as she is currently playing 9% better than Charlotte Weldrake. Alice Clark 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 Alice Clark played 57% better than Charlotte Weldrake in this match. Assuming that any level changes are shared between both players, for this result it looks like Alice Clark actually played at a level of 1,192 and Charlotte Weldrake at a level of 759. Without any damping, both players would need to be adjusted by 20% to match this result. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Alice Clark changes to +18% and Charlotte Weldrake changes to -19%. After applying standard match damping, the adjustment for Alice Clark becomes +10.3% and for Charlotte Weldrake becomes -10.8%. Apply match/event weighting of 75% for 'Womens Ladies Spring 2019 2017/2018' so the adjustment for Alice Clark is +7.7% and for Charlotte Weldrake is -7.9%. 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 Charlotte Weldrake 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. Alice Clark: 89%, Charlotte Weldrake: 87%. Reduce level confidence based on how unexpected the result is. Alice Clark: 74%, Charlotte Weldrake: 72%. 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 Alice Clark: 1,060, level confidence: 74%. Final level for Charlotte Weldrake: 881, level confidence: 72%. Notes
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