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Login: | Explaining level changesDivision 4A: Keynsham v Hutton Moor A (Wed 09 Mar 2011)Match played between Ryan Bedford (home) and John Wright (away).Match won by Ryan Bedford. Result: 9-3,9-1,5-9,9-7. Starting level for Ryan Bedford: 518, level confidence: 78%. Set manually. Starting level for John Wright: 681, level confidence: 75%. Set manually. John Wright to win as he is currently playing 31% better than Ryan Bedford. Ryan Bedford won 75% of the games and 62% 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 29% (english scoring). These are weighted and combined to calculate that Ryan Bedford played 26% better than John Wright in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Ryan Bedford actually played at a level of 668 and John Wright at a level of 528. Without any damping, both players would need to be adjusted by 29% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 25% and 25% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Ryan Bedford changes to +24% and John Wright changes to -25%. After applying standard match damping, the adjustment for Ryan Bedford becomes +12.9% and for John Wright becomes -13%. Apply match/event weighting of 75% for 'Mixed Spring 2011' so the adjustment for Ryan Bedford is +9.7% and for John Wright is -9.7%. 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 John Wright 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. Ryan Bedford: 88%, John Wright: 86%. Reduce level confidence based on how unexpected the result is. Ryan Bedford: 69%, John Wright: 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 Ryan Bedford: 567, level confidence: 69%. Final level for John Wright: 648, level confidence: 67%. Notes
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