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Login: | Explaining level changesDivision 2: Gordano A v Chew Valley Winter A (Wed 21 Mar 2018)Match played between Tony Pigrem (home) and Richard Nichol (away).Match won by Richard Nichol. Result: 4-9,5-9,5-9. Starting level for Tony Pigrem: 1,743, level confidence: 74%. Set manually. Starting level for Richard Nichol: 1,532, level confidence: 70%. Tony Pigrem to win as he is currently playing 14% better than Richard Nichol. Richard Nichol won all of the games and 66% 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 41% (english scoring). These are weighted and combined to calculate that Richard Nichol played 46% better than Tony Pigrem in this match. Assuming that any level changes are shared between both players, for this result it looks like Richard Nichol actually played at a level of 1,972 and Tony Pigrem at a level of 1,354. Without any damping, both players would need to be adjusted by 29% 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 Richard Nichol changes to +27% and Tony Pigrem changes to -25%. After applying standard match damping, the adjustment for Richard Nichol becomes +11.9% and for Tony Pigrem becomes -10.7%. Apply match/event weighting of 75% for 'Mixed Spring 2017/2018' so the adjustment for Richard Nichol is +8.9% and for Tony Pigrem is -7.8%. 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 Tony Pigrem 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. Richard Nichol: 83%, Tony Pigrem: 86%. Reduce level confidence based on how unexpected the result is. Richard Nichol: 65%, Tony Pigrem: 67%. A final adjustment of -0.2% 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 Tony Pigrem: 1,658, level confidence: 67%. Final level for Richard Nichol: 1,664, level confidence: 65%. Notes
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