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Login: | Explaining level changesDivision 1A: Whitchurch Imperial v Gordano B (Wed 30 Oct 2013)Match played between Neal Mathias (home) and Steve Gale (away).Match won by Steve Gale. Result: 5-9,9-7,7-9,7-9:9-3,9-2,9-5:9-2,9-1,9-3:9-7,10-8,9-3:9-0,9-3,9-5. Starting level for Neal Mathias: 1,607, level confidence: 31%. Starting level for Steve Gale: 1,353, level confidence: 71%. Set manually. Neal Mathias to win as he is currently playing 19% better than Steve Gale. Steve Gale won 75% of the games and 55% of the points. This games result would be expected if he was better by around 25%. This points result would be expected if he was better by around 11% (english scoring). These are weighted and combined to calculate that Steve Gale played 20% better than Neal Mathias in this match. Assuming that any level changes are shared between both players, for this result it looks like Steve Gale actually played at a level of 1,618 and Neal Mathias at a level of 1,344. Without any damping, both players would need to be adjusted by 20% 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 Steve Gale changes to +7.8% and Neal Mathias changes to -18%. After applying standard match damping, the adjustment for Steve Gale becomes +4.7% and for Neal Mathias becomes -8.4%. Apply match/event weighting of 75% for 'Mixed Autumn 2013/2014' so the adjustment for Steve Gale is +3.5% and for Neal Mathias is -6.2%. 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 Neal Mathias 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. Steve Gale: 84%, Neal Mathias: 56%. Reduce level confidence based on how unexpected the result is. Steve Gale: 70%, Neal Mathias: 47%. A final adjustment of +0.3% 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 Neal Mathias: 1,533, level confidence: 47%. Final level for Steve Gale: 1,406, level confidence: 70%. Notes
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