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Login: | Explaining level changesDivision 1: Thornbury A v Gordano A (Wed 20 Oct 2021)Match played between Ian Johnson (home) and Steve Gale (away).Match won by Steve Gale. Result: 9-15,10-15,15-8,11-15. Starting level for Ian Johnson: 2,048, level confidence: 55%. Starting level for Steve Gale: 1,663, level confidence: 82%. Set manually. Ian Johnson to win as he is currently playing 23% better than Steve Gale. Steve Gale won 75% of the games and 54% of the points. This games result would be expected if he was better by around 25%. This points result would be expected if he was better by around 18% (PAR scoring). These are weighted and combined to calculate that Steve Gale played 23% better than Ian Johnson in this match. Assuming that any level changes are shared between both players, for this result it looks like Steve Gale actually played at a level of 2,044 and Ian Johnson at a level of 1,667. Without any damping, both players would need to be adjusted by 23% to match this result. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Steve Gale changes to +14% and Ian Johnson changes to -20%. After applying standard match damping, the adjustment for Steve Gale becomes +6.7% and for Ian Johnson becomes -8.6%. Apply match/event weighting of 75% for 'Mixed Autumn 2021/2022' so the adjustment for Steve Gale is +5% and for Ian Johnson 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 Ian Johnson 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. Steve Gale: 90%, Ian Johnson: 74%. Reduce level confidence based on how unexpected the result is. Steve Gale: 73%, Ian Johnson: 60%. 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 Ian Johnson: 1,948, level confidence: 60%. Final level for Steve Gale: 1,744, level confidence: 73%. Notes
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