Menu | Explaining level changesPeter Karran v Chandra Khoda (Wed 18 Dec 2019)Match won by Chandra Khoda. Result: 12-15,11-15,13-15.Starting level for Peter Karran: 937, level confidence: 56%. Starting level for Chandra Khoda: 637, level confidence: 52%. Peter Karran to win as he is currently playing 47% better than Chandra Khoda. Chandra Khoda won all of the games and 56% of the points. This games result would be expected if he was better by around 55% or more. This points result would be expected if he was better by around 25% (PAR scoring). These are weighted and combined to calculate that Chandra Khoda played 35% better than Peter Karran in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Chandra Khoda actually played at a level of 897 and Peter Karran at a level of 665. Without any damping, both players would need to be adjusted by 41% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 33% and 33% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Chandra Khoda changes to +33% and Peter Karran changes to -30%. After applying standard match damping, the adjustment for Chandra Khoda becomes +16.9% and for Peter Karran becomes -16%. Apply match/event weighting of 50% for 'Finchley Manor Boxes' so the adjustment for Chandra Khoda is +8.4% and for Peter Karran is -7.3%. 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 Peter Karran 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. Chandra Khoda: 72%, Peter Karran: 75%. Reduce level confidence based on how unexpected the result is. Chandra Khoda: 51%, Peter Karran: 53%. A final adjustment of -0.1% 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 Peter Karran: 891, level confidence: 53%. Final level for Chandra Khoda: 690, level confidence: 51%. Notes
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