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Login: | Explaining level changesDivision 5: Redland Fireflies v Keynsham (Thu 22 Feb 2018)Match played between Calum Philip (home) and Kevin Ward (away).Match won by Calum Philip. Result: 9-5,9-4,9-6:9-5,6-9,5-9,9-5,9-8:9-5,9-4,9-2:9-3,1-9,9-3,6-9,9-10:9-1,9-1,2-9,9-1. Starting level for Calum Philip: 1,314, level confidence: 85%. Set manually. Starting level for Kevin Ward: 1,639, level confidence: 69%. Kevin Ward to win as he is currently playing 25% better than Calum Philip. Calum Philip 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 35% (english scoring). These are weighted and combined to calculate that Calum Philip played 42% better than Kevin Ward in this match. Assuming that any level changes are shared between both players, for this result it looks like Calum Philip actually played at a level of 1,746 and Kevin Ward at a level of 1,233. Without any damping, both players would need to be adjusted by 33% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 29% and 29% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Calum Philip changes to +23% and Kevin Ward changes to -29%. After applying standard match damping, the adjustment for Calum Philip becomes +11.3% and for Kevin Ward becomes -12%. Apply match/event weighting of 75% for 'Mixed Spring 2017/2018' so the adjustment for Calum Philip is +8.5% and for Kevin Ward is -9.1%. 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 Kevin Ward is limited to -6.1% 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. Calum Philip: 92%, Kevin Ward: 83%. Reduce level confidence based on how unexpected the result is. Calum Philip: 69%, Kevin Ward: 62%. A final adjustment of -1.1% 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 Calum Philip: 1,398, level confidence: 69%. Final level for Kevin Ward: 1,543, level confidence: 62%. Notes
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