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Login: | Explaining level changesDivision 2: Kingsdown v Redland Winter Pumas (Thu 30 Mar 2023)Match played between Pauline Butcher (home) and Emily Pendrell (away).Match won by Emily Pendrell. Result: 8-15,12-15,15-8,15-11,11-15. Starting level for Pauline Butcher: 415, level confidence: 55%. Starting level for Emily Pendrell: 317, level confidence: 75%. Set manually. Pauline Butcher to win as she is currently playing 31% better than Emily Pendrell. Emily Pendrell won 60% of the games and 51% of the points. This games result would be expected if she was better by around 10%. This points result would be expected if she was better by around 5% (PAR scoring). These are weighted and combined to calculate that Emily Pendrell played 9% better than Pauline Butcher in this match. Assuming that any level changes are shared between both players, for this result it looks like Emily Pendrell actually played at a level of 378 and Pauline Butcher at a level of 348. Without any damping, both players would need to be adjusted by 19% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 17% and 17% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Emily Pendrell changes to +12% and Pauline Butcher changes to -17%. After applying standard match damping, the adjustment for Emily Pendrell becomes +7.5% and for Pauline Butcher becomes -9.7%. Apply match/event weighting of 75% for 'Womens Womans Spring 2022/2023' so the adjustment for Emily Pendrell is +5.6% and for Pauline Butcher is -7.1%. 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 Pauline Butcher 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. Emily Pendrell: 87%, Pauline Butcher: 74%. Reduce level confidence based on how unexpected the result is. Emily Pendrell: 73%, Pauline Butcher: 62%. A final adjustment of -1.2% 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 Pauline Butcher: 395, level confidence: 62%. Final level for Emily Pendrell: 327, level confidence: 73%. Notes
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