Menu | Explaining level changesBobbi Davis v Andrew Purr (Thu 02 Nov 2023)Match won by Andrew Purr. Result: 2-11,5-11,4-11.Starting level for Bobbi Davis: 272, level confidence: 78%. Set manually. Starting level for Andrew Purr: 435, level confidence: 41%. Andrew Purr to win as he is currently playing 60% better than Bobbi Davis. Andrew Purr won all of the games and 75% 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 200% (PAR scoring). These are weighted and combined to calculate that Andrew Purr played 200% better than Bobbi Davis in this match. Andrew Purr has played significantly better in this match than his level suggests and this is backed up by his last three results so use accelerated level adjustment to get his level right more quickly. As a result, his pre-match level has been increased to 482. The remaining calculations use this as his level coming in to this match. Assuming that any level changes are shared between both players, for this result it looks like Andrew Purr actually played at a level of 627 and Bobbi Davis at a level of 209. 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 21% 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 Andrew Purr changes to +21% and Bobbi Davis changes to -10.3%. After applying standard match damping, the adjustment for Andrew Purr becomes +11.5% and for Bobbi Davis becomes -6.6%. Apply match/event weighting of 50% for 'Fair Oak Boxes' so the adjustment for Andrew Purr is +5.7% and for Bobbi Davis is -3.2%. Including the accelerated level adjustment, the total adjustment for Andrew Purr is +17%. Increase level confidence due to one more match played. Andrew Purr: 64%, Bobbi Davis: 89%. Reduce level confidence based on how unexpected the result is. Andrew Purr: 47%, Bobbi Davis: 65%. A final adjustment of -0.3% 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 Bobbi Davis: 263, level confidence: 65%. Final level for Andrew Purr: 509, level confidence: 47%. Notes
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