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Login: | Explaining level changesDave Hughes v Peter Phelps (Sat 08 Apr 2017)Match won by Peter Phelps. Result: 1-9,2-9,2-9.Starting level for Dave Hughes: 308, level confidence: 80%. Set manually. Starting level for Peter Phelps: 426, level confidence: 80%. Set manually. Peter Phelps to win as he is currently playing 38% better than Dave Hughes. Peter Phelps won all of the games and 84% 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 134% (english scoring). These are weighted and combined to calculate that Peter Phelps played 134% better than Dave Hughes in this match. Assuming that any level changes are shared between both players, for this result it looks like Peter Phelps actually played at a level of 554 and Dave Hughes at a level of 237. Without any damping, both players would need to be adjusted by 30% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 25% and 25% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Peter Phelps changes to +25% and Dave Hughes changes to -25%. After applying standard match damping, the adjustment for Peter Phelps becomes +13.5% and for Dave Hughes becomes -13%. Apply match/event weighting of 50% for 'Kingswood Boxes' so the adjustment for Peter Phelps is +6.7% and for Dave Hughes is -6.3%. 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 Dave Hughes 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. Peter Phelps: 89%, Dave Hughes: 90%. Reduce level confidence based on how unexpected the result is. Peter Phelps: 69%, Dave Hughes: 69%. 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 Dave Hughes: 293, level confidence: 69%. Final level for Peter Phelps: 454, level confidence: 69%. Notes
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