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Login: | Explaining level changesDivision 2: Thornbury v Hutton Moor (Thu 25 Feb 2010)Match played between Maryann Neudegg (home) and Karen Lawrenson (away).Match won by Karen Lawrenson. Result: 1-9,5-9,2-9. Starting level for Maryann Neudegg: 199, level confidence: 83%. Set manually. Starting level for Karen Lawrenson: 239, level confidence: 72%. Set manually. Karen Lawrenson to win as she is currently playing 20% better than Maryann Neudegg. Karen Lawrenson won all of the games and 77% of the points. This games result would be expected if she was better by around 55% or more. This points result would be expected if she was better by around 86% (english scoring). These are weighted and combined to calculate that Karen Lawrenson played 86% better than Maryann Neudegg in this match. Assuming that any level changes are shared between both players, for this result it looks like Karen Lawrenson actually played at a level of 297 and Maryann Neudegg at a level of 160. Without any damping, both players would need to be adjusted by 24% 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 Karen Lawrenson changes to +22% and Maryann Neudegg changes to -19%. After applying standard match damping, the adjustment for Karen Lawrenson becomes +12.1% and for Maryann Neudegg becomes -10.6%. Apply match/event weighting of 75% for 'Womens Winter 2009/2010' so the adjustment for Karen Lawrenson is +9.1% and for Maryann Neudegg 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 Maryann Neudegg 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. Karen Lawrenson: 85%, Maryann Neudegg: 91%. Reduce level confidence based on how unexpected the result is. Karen Lawrenson: 68%, Maryann Neudegg: 73%. A final adjustment of -0.5% 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 Maryann Neudegg: 189, level confidence: 73%. Final level for Karen Lawrenson: 260, level confidence: 68%. Notes
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