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Login: | Explaining level changesJames Cowan v Tamsin Pascoe (Tue 09 May 2017)Match won by James Cowan. Result: 9-4,9-8,7-9,9-5.Starting level for James Cowan: 455, level confidence: 69%. Starting level for Tamsin Pascoe: 576, level confidence: 58%. Tamsin Pascoe to win as she is currently playing 27% better than James Cowan. James Cowan won 75% of the games and 57% of the points. This games result would be expected if he was better by around 25%. This points result would be expected if he was better by around 16% (english scoring). These are weighted and combined to calculate that James Cowan played 22% better than Tamsin Pascoe in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like James Cowan actually played at a level of 566 and Tamsin Pascoe at a level of 463. Without any damping, both players would need to be adjusted by 24% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 21% and 21% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for James Cowan changes to +18% and Tamsin Pascoe changes to -21%. After applying standard match damping, the adjustment for James Cowan becomes +10.2% and for Tamsin Pascoe becomes -12%. Apply match/event weighting of 50% for 'Redland Green Boxes' so the adjustment for James Cowan is +5.1% and for Tamsin Pascoe is -5.6%. 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 Tamsin Pascoe 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. James Cowan: 83%, Tamsin Pascoe: 76%. Reduce level confidence based on how unexpected the result is. James Cowan: 67%, Tamsin Pascoe: 61%. A final adjustment of +0.9% 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 James Cowan: 477, level confidence: 67%. Final level for Tamsin Pascoe: 560, level confidence: 61%. Notes
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