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Login: | Explaining level changesNathan Woodhead v Ben Lawes (Sat 10 Nov 2012)Match won by Nathan Woodhead. Result: 11-6,11-7,11-6.Starting level for Nathan Woodhead: 1,437, level confidence: 42%. Starting level for Ben Lawes: 3,257, level confidence: 31%. Ben Lawes to win as he is currently playing 127% better than Nathan Woodhead. Nathan Woodhead won all of the games and 63% 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 74% (PAR scoring). These are weighted and combined to calculate that Nathan Woodhead played 74% better than Ben Lawes in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Nathan Woodhead actually played at a level of 2,851 and Ben Lawes at a level of 1,642. Without any damping, both players would need to be adjusted by 98% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 58% and 58% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Nathan Woodhead changes to +44% and Ben Lawes changes to -58%. After applying standard match damping, the adjustment for Nathan Woodhead becomes +18.4% and for Ben Lawes becomes -17%. Apply match/event weighting of 100% for 'Avon Junior Closed' so the adjustment is unchanged. 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 Nathan Woodhead is limited to +10% and Ben Lawes 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. Nathan Woodhead: 64%, Ben Lawes: 56%. Reduce level confidence based on how unexpected the result is. Nathan Woodhead: 32%, Ben Lawes: 28%. A final adjustment of -1.4% 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 Nathan Woodhead: 1,533, level confidence: 32%. Final level for Ben Lawes: 3,110, level confidence: 28%. Notes
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