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Login: | Explaining level changesAlex Taylor v Mark Bishop (Wed 25 Apr 2018)Match won by Alex Taylor. Result: 10-9,0-9,9-1,9-2.Starting level for Alex Taylor: 784, level confidence: 78%. Set manually. Starting level for Mark Bishop: 999, level confidence: 57%. Mark Bishop to win as he is currently playing 27% better than Alex Taylor. Alex Taylor 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 Alex Taylor played 22% better than Mark Bishop in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Alex Taylor actually played at a level of 978 and Mark Bishop at a level of 801. Without any damping, both players would need to be adjusted by 25% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 22% and 22% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Alex Taylor changes to +16% and Mark Bishop changes to -22%. After applying standard match damping, the adjustment for Alex Taylor becomes +9.3% and for Mark Bishop becomes -12%. Apply match/event weighting of 50% for 'Westbury David Lloyd Boxes' so the adjustment for Alex Taylor is +4.6% and for Mark Bishop 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 Mark Bishop 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. Alex Taylor: 88%, Mark Bishop: 76%. Reduce level confidence based on how unexpected the result is. Alex Taylor: 71%, Mark Bishop: 61%. A final adjustment of -9.8% 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 Alex Taylor: 809, level confidence: 71%. Final level for Mark Bishop: 799, level confidence: 61%. Notes
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