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Login: | Explaining level changesDivision 5: Keynsham v Kingsdown Stallions (Wed 17 Feb 2016)Match played between Shane Davis (home) and David Mortimer (away).Match won by Shane Davis. Result: 6-9,9-6,9-7,9-6. Starting level for Shane Davis: 720, level confidence: 78%. Set manually. Starting level for David Mortimer: 761, level confidence: 57%. David Mortimer to win as he is currently playing 6% better than Shane Davis. Shane Davis 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 9% (english scoring). These are weighted and combined to calculate that Shane Davis played 20% better than David Mortimer in this match. Assuming that any level changes are shared between both players, for this result it looks like Shane Davis actually played at a level of 810 and David Mortimer at a level of 677. Without any damping, both players would need to be adjusted by 12% 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 Shane Davis changes to +8.8% and David Mortimer changes to -12%. After applying standard match damping, the adjustment for Shane Davis becomes +5.9% and for David Mortimer becomes -7.5%. Apply match/event weighting of 75% for 'Mixed Spring 2015/2016' so the adjustment for Shane Davis is +4.4% and for David Mortimer is -5.5%. 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 David Mortimer 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. Shane Davis: 89%, David Mortimer: 76%. Reduce level confidence based on how unexpected the result is. Shane Davis: 79%, David Mortimer: 67%. 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 Shane Davis: 751, level confidence: 79%. Final level for David Mortimer: 724, level confidence: 67%. Notes
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