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Login: | Explaining level changesBen Lawes v Ewan Joyce (Sun 11 Nov 2012)Match won by Ben Lawes. Result: 8-11,11-8,11-9,8-11,11-9.Starting level for Ben Lawes: 3,430, level confidence: 25%. Starting level for Ewan Joyce: 6,399, level confidence: 26%. Ewan Joyce to win as he is currently playing 87% better than Ben Lawes. Ben Lawes won 60% of the games and 51% of the points. This games result would be expected if he was better by around 10%. This points result would be expected if he was better by around 2% (PAR scoring). These are weighted and combined to calculate that Ben Lawes played 8% better than Ewan Joyce in this match. Assuming that any level changes are shared between both players, for this result it looks like Ben Lawes actually played at a level of 4,869 and Ewan Joyce at a level of 4,508. Without any damping, both players would need to be adjusted by 42% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 29% and 29% 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 Lawes changes to +29% and Ewan Joyce changes to -29%. After applying standard match damping, the adjustment for Ben Lawes becomes +9.8% and for Ewan Joyce becomes -8.1%. 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 Ewan Joyce 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. Ben Lawes has already increased 18% since starting this event at level 2918. The amount a player can increase in a single event is limited to 25% so Ben Lawes's increase for this match has been limited to 6.3%. Increase level confidence due to one more match played. Ben Lawes: 50%, Ewan Joyce: 51%. Reduce level confidence based on how unexpected the result is. Ben Lawes: 35%, Ewan Joyce: 36%. 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 Lawes: 3,648, level confidence: 35%. Final level for Ewan Joyce: 6,170, level confidence: 36%. Notes
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