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Login: | Explaining level changesDivision 1A: Gordano A v Westbury David Lloyd A (Wed 18 Mar 2015)Match played between Edwin Swidenbank (home) and Kirk Woodward (away).Match won by Edwin Swidenbank. Result: 9-3,9-5,9-5. Starting level for Edwin Swidenbank: 1,777, level confidence: 74%. Set manually. Starting level for Kirk Woodward: 2,413, level confidence: 66%. Kirk Woodward to win as he is currently playing 36% better than Edwin Swidenbank. Edwin Swidenbank won all of the games and 68% 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 48% (english scoring). These are weighted and combined to calculate that Edwin Swidenbank played 50% better than Kirk Woodward in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Edwin Swidenbank actually played at a level of 2,539 and Kirk Woodward at a level of 1,689. Without any damping, both players would need to be adjusted by 43% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 36% and 36% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Edwin Swidenbank changes to +32% and Kirk Woodward changes to -36%. After applying standard match damping, the adjustment for Edwin Swidenbank becomes +13% and for Kirk Woodward becomes -13%. Apply match/event weighting of 75% for 'Mixed Spring 2014/2015' so the adjustment for Edwin Swidenbank is +9.7% and for Kirk Woodward is -9.4%. 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 Kirk Woodward 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. Edwin Swidenbank: 86%, Kirk Woodward: 81%. Reduce level confidence based on how unexpected the result is. Edwin Swidenbank: 60%, Kirk Woodward: 57%. A final adjustment of -0.1% 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 Edwin Swidenbank: 1,947, level confidence: 60%. Final level for Kirk Woodward: 2,295, level confidence: 57%. Notes
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