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Login: | Explaining level changesDivision 2: University of Bristol Beasts v Kingsdown (Thu 09 Nov 2017)Match played between Georgia Blatchford (home) and Mary Walkerdine (away).Match won by Georgia Blatchford. Result: 9-1,9-4,9-2. Starting level for Georgia Blatchford: 177, level confidence: 43%. Starting level for Mary Walkerdine: 161, level confidence: 55%. Georgia Blatchford to win as she is currently playing 10% better than Mary Walkerdine. Georgia Blatchford won all of the games and 79% 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 97% (english scoring). These are weighted and combined to calculate that Georgia Blatchford played 97% better than Mary Walkerdine in this match. Assuming that any level changes are shared between both players, for this result it looks like Georgia Blatchford actually played at a level of 237 and Mary Walkerdine at a level of 120. Without any damping, both players would need to be adjusted by 34% 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 Georgia Blatchford changes to +32% and Mary Walkerdine changes to -24%. After applying standard match damping, the adjustment for Georgia Blatchford becomes +16.6% and for Mary Walkerdine becomes -13%. Apply match/event weighting of 75% for 'Womens Ladies Winter 2017/2018' so the adjustment for Georgia Blatchford is +12% and for Mary Walkerdine is -9.4%. 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 Georgia Blatchford is limited to +10% and Mary Walkerdine is limited to -5.8% 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. Georgia Blatchford: 66%, Mary Walkerdine: 74%. Reduce level confidence based on how unexpected the result is. Georgia Blatchford: 49%, Mary Walkerdine: 55%. 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 Georgia Blatchford: 195, level confidence: 49%. Final level for Mary Walkerdine: 153, level confidence: 55%. Notes
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