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Login: | Explaining level changesDivision 3B: Kingswood Originals v Keynsham (Wed 25 Feb 2015)Match played between Neale Saunders (home) and Shaun Spear (away).Match won by Adrian Robbins. Result: 3-9,4-9,9-3,9-10,9-5. Starting level for Neale Saunders: 724, level confidence: 56%. Starting level for Adrian Robbins: 365, level confidence: 82%. Set manually. Neale Saunders to win as he is currently playing 98% better than Adrian Robbins. Adrian Robbins won 60% of the games and 51% 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 2% (english scoring). These are weighted and combined to calculate that Adrian Robbins played 8% better than Neale Saunders in this match. Assuming that any level changes are shared between both players, for this result it looks like Adrian Robbins actually played at a level of 534 and Neale Saunders at a level of 495. Without any damping, both players would need to be adjusted by 46% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 31% and 31% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Adrian Robbins changes to +21% and Neale Saunders changes to -31%. After applying standard match damping, the adjustment for Adrian Robbins becomes +11.7% and for Neale Saunders becomes -16%. Apply match/event weighting of 75% for 'Mixed Spring 2014/2015' so the adjustment for Adrian Robbins is +8.8% and for Neale Saunders is -12%. 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 Neale Saunders 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. Adrian Robbins: 90%, Neale Saunders: 75%. Reduce level confidence based on how unexpected the result is. Adrian Robbins: 62%, Neale Saunders: 51%. A final adjustment of -0.3% 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 Neale Saunders: 688, level confidence: 51%. Final level for Adrian Robbins: 396, level confidence: 62%. Notes
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