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Login: | Explaining level changesDivision 3: Thornbury B v Weston Shankers (Wed 13 Oct 2021)Match played between Nick Clifton (home) and Paul McLean (away).Match won by Nick Clifton. Result: 15-7,15-4,17-15:13-15,15-13,7-15,5-15:16-14,15-13,15-8:15-8,10-15,15-4,15-7:15-8,15-12,15-10. Starting level for Nick Clifton: 1,924, level confidence: 71%. Set manually. Starting level for Paul McLean: 1,469, level confidence: 10%. Nick Clifton to win as he is currently playing 31% better than Paul McLean. Nick Clifton won all of the games and 64% 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 81% (PAR scoring). These are weighted and combined to calculate that Nick Clifton played 81% better than Paul McLean in this match. Assuming that any level changes are shared between both players, for this result it looks like Nick Clifton actually played at a level of 2,260 and Paul McLean at a level of 1,250. Without any damping, both players would need to be adjusted by 17% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 15% and 15% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Nick Clifton changes to +2.1% and Paul McLean changes to -15%. After applying standard match damping, the adjustment for Nick Clifton becomes +1.7% and for Paul McLean becomes -7.6%. Apply match/event weighting of 75% for 'Mixed Autumn 2021/2022' so the adjustment for Nick Clifton is +1.2% and for Paul McLean 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 Paul McLean 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. Nick Clifton: 84%, Paul McLean: 32%. Reduce level confidence based on how unexpected the result is. Nick Clifton: 72%, Paul McLean: 27%. 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 Nick Clifton: 1,946, level confidence: 72%. Final level for Paul McLean: 1,398, level confidence: 27%. Notes
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