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Login: | Explaining level changesMichelle Morgan v Phil Eaton (Wed 17 May 2017)Match won by Michelle Morgan. Result: 9-6,9-5,9-4.Starting level for Michelle Morgan: 209, level confidence: 52%. Starting level for Phil Eaton: 284, level confidence: 46%. Phil Eaton to win as he is currently playing 36% better than Michelle Morgan. Michelle Morgan won all of the games and 64% 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 35% (english scoring). These are weighted and combined to calculate that Michelle Morgan played 42% better than Phil Eaton in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Michelle Morgan actually played at a level of 290 and Phil Eaton at a level of 205. Without any damping, both players would need to be adjusted by 39% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 32% and 32% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Michelle Morgan changes to +28% and Phil Eaton changes to -32%. After applying standard match damping, the adjustment for Michelle Morgan becomes +15% and for Phil Eaton becomes -17%. Apply match/event weighting of 50% for 'Redland Green Boxes' so the adjustment for Michelle Morgan is +7.5% and for Phil Eaton is -7.8%. 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 Phil Eaton 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. Michelle Morgan: 72%, Phil Eaton: 68%. Reduce level confidence based on how unexpected the result is. Michelle Morgan: 52%, Phil Eaton: 49%. 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 Michelle Morgan: 224, level confidence: 52%. Final level for Phil Eaton: 270, level confidence: 49%. Notes
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