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Login: | Explaining level changesDivision 4: Redwood Phoenix v Whitchurch Imperial A (Wed 22 Feb 2017)Match played between Ben Swift (home) and Gary Loughran (away).Match won by Ben Swift. Result: 9-3,9-1,9-1:9-3,8-10,9-10,9-6,9-3:9-7,9-10,9-7,2-9,9-5:9-5,9-1,9-4:9-6,9-0,9-4. Starting level for Ben Swift: 1,978, level confidence: 53%. Starting level for Gary Loughran: 1,414, level confidence: 76%. Set manually. Ben Swift to win as he is currently playing 40% better than Gary Loughran. Ben Swift won all of the games and 84% 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 134% (english scoring). These are weighted and combined to calculate that Ben Swift played 134% better than Gary Loughran in this match. Assuming that any level changes are shared between both players, for this result it looks like Ben Swift actually played at a level of 2,558 and Gary Loughran at a level of 1,093. Without any damping, both players would need to be adjusted by 29% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 24% and 24% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Ben Swift changes to +24% and Gary Loughran changes to -16%. After applying standard match damping, the adjustment for Ben Swift becomes +10% and for Gary Loughran becomes -7.9%. Apply match/event weighting of 75% for 'Mixed Spring 2016/2017' so the adjustment for Ben Swift is +7.5% and for Gary Loughran is -5.8%. 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 Gary Loughran 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. Ben Swift: 72%, Gary Loughran: 87%. Reduce level confidence based on how unexpected the result is. Ben Swift: 56%, Gary Loughran: 67%. A final adjustment of -0.6% 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 Ben Swift: 2,103, level confidence: 56%. Final level for Gary Loughran: 1,345, level confidence: 67%. Notes
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