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Login: | Explaining level changesPremier B: University of Bristol Chiefs v David Lloyd A (Thu 05 Feb 2015)Match played between Henry Duncanson (home) and Simon Hygate (away).Match won by Henry Duncanson. Result: 9-6,3-9,9-8,9-5. Starting level for Henry Duncanson: 2,884, level confidence: 67%. Starting level for Simon Hygate: 4,899, level confidence: 53%. Simon Hygate to win as he is currently playing 70% better than Henry Duncanson. Henry Duncanson won 75% of the games and 52% 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 4% (english scoring). These are weighted and combined to calculate that Henry Duncanson played 18% better than Simon Hygate in this match. Assuming that any level changes are shared between both players, for this result it looks like Henry Duncanson actually played at a level of 4,084 and Simon Hygate at a level of 3,459. Without any damping, both players would need to be adjusted by 42% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 31% and 31% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Henry Duncanson changes to +24% and Simon Hygate changes to -31%. After applying standard match damping, the adjustment for Henry Duncanson becomes +8.8% and for Simon Hygate becomes -9.2%. Apply match/event weighting of 75% for 'Mixed Spring 2014/2015' so the adjustment for Henry Duncanson is +6.6% and for Simon Hygate is -6.7%. 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 Simon Hygate 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. Henry Duncanson: 82%, Simon Hygate: 73%. Reduce level confidence based on how unexpected the result is. Henry Duncanson: 58%, Simon Hygate: 51%. A final adjustment of +0.7% 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 Henry Duncanson: 3,070, level confidence: 58%. Final level for Simon Hygate: 4,735, level confidence: 51%. Notes
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