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Login: | Explaining level changesMatthew Smith v Ruth Drysdale (Mon 26 Jun 2023)Match won by Ruth Drysdale. Result: 9-15,6-15,2-15.Starting level for Matthew Smith: 575, level confidence: 71%. Set manually. Starting level for Ruth Drysdale: 671, level confidence: 60%. Ruth Drysdale to win as she is currently playing 17% better than Matthew Smith. Ruth Drysdale 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 165% (PAR scoring). These are weighted and combined to calculate that Ruth Drysdale played 165% better than Matthew Smith in this match. Assuming that any level changes are shared between both players, for this result it looks like Ruth Drysdale actually played at a level of 1,011 and Matthew Smith at a level of 382. Without any damping, both players would need to be adjusted by 51% 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 Ruth Drysdale changes to +46% and Matthew Smith changes to -36%. After applying standard match damping, the adjustment for Ruth Drysdale becomes +22.6% and for Matthew Smith becomes -18%. Apply match/event weighting of 50% for 'Redland Green Boxes' so the adjustment for Ruth Drysdale is +11% and for Matthew Smith is -8.4%. 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 Ruth Drysdale is limited to +10% and Matthew Smith 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. Ruth Drysdale: 77%, Matthew Smith: 85%. Reduce level confidence based on how unexpected the result is. Ruth Drysdale: 51%, Matthew Smith: 56%. 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 Matthew Smith: 547, level confidence: 56%. Final level for Ruth Drysdale: 737, level confidence: 51%. Notes
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