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Login: | Explaining level changesDivision 2: Thornbury B v Redland Fireflies (Wed 12 Apr 2023)Match played between Nigel Ball (home) and Mark Beech (away).Match won by Nigel Ball. Result: 16-14,9-15,15-9,13-15,16-14. Starting level for Nigel Ball: 1,243, level confidence: 72%. Set manually. Starting level for Mark Beech: 1,895, level confidence: 75%. Set manually. Mark Beech to win as he is currently playing 52% better than Nigel Ball. Nigel Ball won 60% of the games and 51% of the points. This games result would be expected if he was better by around 10%. This points result would be expected if he was better by around 3% (PAR scoring). These are weighted and combined to calculate that Nigel Ball played 8% better than Mark Beech in this match. Assuming that any level changes are shared between both players, for this result it looks like Nigel Ball actually played at a level of 1,597 and Mark Beech at a level of 1,475. Without any damping, both players would need to be adjusted by 28% 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 Nigel Ball changes to +22% and Mark Beech changes to -21%. After applying standard match damping, the adjustment for Nigel Ball becomes +11.2% and for Mark Beech becomes -9.2%. Apply match/event weighting of 75% for 'Mixed Spring 2022/2023' so the adjustment for Nigel Ball is +8.4% and for Mark Beech is -6.7%. 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 Beech 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. Nigel Ball: 85%, Mark Beech: 87%. Reduce level confidence based on how unexpected the result is. Nigel Ball: 66%, Mark Beech: 67%. A final adjustment of -0.2% 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 Nigel Ball: 1,345, level confidence: 66%. Final level for Mark Beech: 1,802, level confidence: 67%. Notes
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