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Login: | Explaining level changesDivision 2: Redland Winter Pumas v University of Bath Ladies B (Thu 15 Feb 2018)Match played between Claire Packwood (home) and Alice O'Keeffe (away).Match won by Claire Packwood. Result: 9-0,9-0,9-2. Starting level for Claire Packwood: 298, level confidence: 67%. Starting level for Alice O'Keeffe: 115, level confidence: 60%. Claire Packwood to win as she is currently playing 159% better than Alice O'Keeffe. Claire Packwood won all of the games and 93% 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 278% (english scoring). These are weighted and combined to calculate that Claire Packwood played 278% better than Alice O'Keeffe in this match. Assuming that any level changes are shared between both players, for this result it looks like Claire Packwood actually played at a level of 360 and Alice O'Keeffe at a level of 95. Without any damping, both players would need to be adjusted by 21% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 12% and 12% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Claire Packwood changes to +11.1% and Alice O'Keeffe changes to -12%. After applying standard match damping, the adjustment for Claire Packwood becomes +7% and for Alice O'Keeffe becomes -7.7%. Apply match/event weighting of 75% for 'Womens Ladies Spring 2019 2017/2018' so the adjustment for Claire Packwood is +5.2% and for Alice O'Keeffe is -5.6%. 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 Alice O'Keeffe 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. Claire Packwood: 82%, Alice O'Keeffe: 77%. Reduce level confidence based on how unexpected the result is. Claire Packwood: 68%, Alice O'Keeffe: 64%. 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 Claire Packwood: 310, level confidence: 68%. Final level for Alice O'Keeffe: 110, level confidence: 64%. Notes
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