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Login: | Explaining level changesDivision 2: David Lloyd A v University of Bath Ladies A (Thu 11 Apr 2019)Match played between Maxine Hobbs (home) and Georgia Mackenzie (away).Match won by Maxine Hobbs. Result: 15-6,15-4,15-5:15-9,15-5,15-9:15-9,15-2,15-5:15-10,15-11,15-11:15-4,15-10,15-9. Starting level for Maxine Hobbs: 1,107, level confidence: 61%. Starting level for Georgia Mackenzie: 703, level confidence: 40%. Maxine Hobbs to win as she is currently playing 57% better than Georgia Mackenzie. Maxine Hobbs won all of the games and 75% 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 200% (PAR scoring). These are weighted and combined to calculate that Maxine Hobbs played 200% better than Georgia Mackenzie in this match. Assuming that any level changes are shared between both players, for this result it looks like Maxine Hobbs actually played at a level of 1,528 and Georgia Mackenzie at a level of 509. Without any damping, both players would need to be adjusted by 38% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 29% and 29% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Maxine Hobbs changes to +19% and Georgia Mackenzie changes to -29%. After applying standard match damping, the adjustment for Maxine Hobbs becomes +10.4% and for Georgia Mackenzie becomes -15%. Apply match/event weighting of 75% for 'Womens Ladies Spring 2018/2019' so the adjustment for Maxine Hobbs is +7.8% and for Georgia Mackenzie is -11%. 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 Georgia Mackenzie is limited to -7.8% 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. Maxine Hobbs: 78%, Georgia Mackenzie: 63%. Reduce level confidence based on how unexpected the result is. Maxine Hobbs: 56%, Georgia Mackenzie: 46%. A final adjustment of +0.7% 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 Maxine Hobbs: 1,194, level confidence: 56%. Final level for Georgia Mackenzie: 660, level confidence: 46%. Notes
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