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Login: | Explaining level changesDivision 1: Thornbury A v David Lloyd A (Wed 31 Aug 2011)Match played between Nigel Tovey/Rob Livingstone (home) and Sarah Brown/Matt Brunet (away).Match won by Sarah Brown/Matt Brunet. Result: 12-15,15-11,11-15,15-12,11-15:15-7,11-15,15-10,15-11. Starting level for Nigel Tovey/Rob Livingstone: 1,895, level confidence: 72%. Set manually. Starting level for Sarah Brown/Matt Brunet: 930, level confidence: 30%. Nigel Tovey/Rob Livingstone to win as he is currently playing 104% better than Sarah Brown/Matt Brunet. Sarah Brown/Matt Brunet won 60% of the games and 52% of the points. This games result would be expected if he was better by around 10%. This points result would be expected if he was better by around 6% (PAR scoring). These are weighted and combined to calculate that Sarah Brown/Matt Brunet played 9% better than Nigel Tovey/Rob Livingstone in this match. Assuming that any level changes are shared between both players, for this result it looks like Sarah Brown/Matt Brunet actually played at a level of 1,386 and Nigel Tovey/Rob Livingstone at a level of 1,271. Without any damping, both players would need to be adjusted by 49% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 32% and 32% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Sarah Brown/Matt Brunet changes to +32% and Nigel Tovey/Rob Livingstone changes to -12%. After applying standard match damping, the adjustment for Sarah Brown/Matt Brunet becomes +16.7% and for Nigel Tovey/Rob Livingstone becomes -5.6%. Apply match/event weighting of 75% for 'Mixed Doubles 2011' so the adjustment for Sarah Brown/Matt Brunet is +13% and for Nigel Tovey/Rob Livingstone is -4.2%. 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 Sarah Brown/Matt Brunet is limited to +10% 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. Sarah Brown/Matt Brunet: 55%, Nigel Tovey/Rob Livingstone: 85%. Reduce level confidence based on how unexpected the result is. Sarah Brown/Matt Brunet: 37%, Nigel Tovey/Rob Livingstone: 57%. Final level for Nigel Tovey/Rob Livingstone: 1,819, level confidence: 57%. Final level for Sarah Brown/Matt Brunet: 1,023, level confidence: 37%. Notes
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