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Login: | Explaining level changesDivision 2A: BAWA v Cheddar Valley n/a (Wed 02 Mar 2011)Match played between Hugh Morgan (home) and Rob Ware (away).Match won by Hugh Morgan. Result: 9-7,9-4,5-9,9-6:8-10,7-9,9-5,9-4,9-7:10-8,2-9,10-8,9-2:7-9,10-8,6-9,9-7,0-9:2-9,1-9,7-9. Starting level for Hugh Morgan: 1,341, level confidence: 85%. Set manually. Starting level for Rob Ware: 1,742, level confidence: 81%. Set manually. Rob Ware to win as he is currently playing 30% better than Hugh Morgan. Hugh Morgan won 75% of the games and 55% 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 11% (english scoring). These are weighted and combined to calculate that Hugh Morgan played 20% better than Rob Ware in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Hugh Morgan actually played at a level of 1,677 and Rob Ware at a level of 1,393. Without any damping, both players would need to be adjusted by 25% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 22% and 22% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Hugh Morgan changes to +21% and Rob Ware changes to -22%. After applying standard match damping, the adjustment for Hugh Morgan becomes +10.1% and for Rob Ware becomes -9.6%. Apply match/event weighting of 75% for 'Mixed Spring 2011' so the adjustment for Hugh Morgan is +7.6% and for Rob Ware is -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 Rob Ware 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. Hugh Morgan: 92%, Rob Ware: 90%. Reduce level confidence based on how unexpected the result is. Hugh Morgan: 74%, Rob Ware: 72%. A final adjustment of -0.2% 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 Hugh Morgan: 1,440, level confidence: 74%. Final level for Rob Ware: 1,657, level confidence: 72%. Notes
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