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Login: | Explaining level changesDivision 7: BAWA v Westbury David Lloyd C (Wed 28 Feb 2018)Match played between Neil Bridle (home) and Ben Winter (away).Match won by Neil Bridle. Result: 9-1,9-1,10-9:1-9,6-9,9-6,4-9:9-2,0-9,7-9,0-9:3-9,2-9,7-9:4-9,9-1,9-2,9-4. Starting level for Neil Bridle: 1,306, level confidence: 66%. Starting level for Ben Winter: 1,186, level confidence: 80%. Set manually. Neil Bridle to win as he is currently playing 10% better than Ben Winter. Neil Bridle won all of the games and 72% 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 63% (english scoring). These are weighted and combined to calculate that Neil Bridle played 63% better than Ben Winter in this match. Assuming that any level changes are shared between both players, for this result it looks like Neil Bridle actually played at a level of 1,589 and Ben Winter at a level of 975. Without any damping, both players would need to be adjusted by 22% 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 Neil Bridle changes to +21% and Ben Winter changes to -16%. After applying standard match damping, the adjustment for Neil Bridle becomes +10.2% and for Ben Winter becomes -8.8%. Apply match/event weighting of 75% for 'Mixed Spring 2017/2018' so the adjustment for Neil Bridle is +7.6% and for Ben Winter is -6.5%. 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 Ben Winter 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. Neil Bridle: 81%, Ben Winter: 90%. Reduce level confidence based on how unexpected the result is. Neil Bridle: 67%, Ben Winter: 74%. A final adjustment of +0.9% 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 Neil Bridle: 1,406, level confidence: 67%. Final level for Ben Winter: 1,150, level confidence: 74%. Notes
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