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Login: | Explaining level changesDivision 3: Keynsham A v Thornbury B (Wed 13 Mar 2024)Match played between David Blake (home) and Ian Johnson (away).Match won by David Blake. Result: 15-11,15-6,15-11:13-15,11-15,9-15:15-13,15-7,14-16,16-14:10-15,10-15,15-9,12-15:15-9,13-15,5-15,11-15. Starting level for David Blake: 1,766, level confidence: 63%. Starting level for Ian Johnson: 1,959, level confidence: 80%. Set manually. Ian Johnson to win as he is currently playing 11% better than David Blake. David Blake won all of the games and 62% 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 61% (PAR scoring). These are weighted and combined to calculate that David Blake played 61% better than Ian Johnson in this match. Assuming that any level changes are shared between both players, for this result it looks like David Blake actually played at a level of 2,358 and Ian Johnson at a level of 1,467. Without any damping, both players would need to be adjusted by 34% 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 David Blake changes to +32% and Ian Johnson changes to -23%. After applying standard match damping, the adjustment for David Blake becomes +13% and for Ian Johnson becomes -9.8%. Apply match/event weighting of 75% for 'Mixed Spring 2023/2024' so the adjustment for David Blake is +9.7% and for Ian Johnson is -7.2%. 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. David Blake: 80%, Ian Johnson: 89%. Reduce level confidence based on how unexpected the result is. David Blake: 60%, Ian Johnson: 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 David Blake: 1,935, level confidence: 60%. Final level for Ian Johnson: 1,863, level confidence: 67%. Notes
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