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Login: | Explaining level changesDivision 1: David Lloyd Battle Oats v University of Bath 2 (Wed 05 Apr 2017)Match played between Joe Coppin (home) and Simon Kirke (away).Match won by Simon Kirke. Result: 6-9,8-9,5-9. Starting level for Joe Coppin: 2,242, level confidence: 75%. Set manually. Starting level for Simon Kirke: 1,886, level confidence: 84%. Set manually. Joe Coppin to win as he is currently playing 19% better than Simon Kirke. Simon Kirke won all of the games and 59% 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 21% (english scoring). These are weighted and combined to calculate that Simon Kirke played 32% better than Joe Coppin in this match. Assuming that any level changes are shared between both players, for this result it looks like Simon Kirke actually played at a level of 2,364 and Joe Coppin at a level of 1,788. Without any damping, both players would need to be adjusted by 25% 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 Simon Kirke changes to +21% and Joe Coppin changes to -23%. After applying standard match damping, the adjustment for Simon Kirke becomes +8.9% and for Joe Coppin becomes -9.2%. Apply match/event weighting of 75% for 'Mixed Spring 2016/2017' so the adjustment for Simon Kirke is +6.7% and for Joe Coppin 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 Joe Coppin 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. Simon Kirke: 92%, Joe Coppin: 87%. Reduce level confidence based on how unexpected the result is. Simon Kirke: 73%, Joe Coppin: 69%. A final adjustment of +0.7% 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 Joe Coppin: 2,162, level confidence: 69%. Final level for Simon Kirke: 2,013, level confidence: 73%. Notes
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