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Login: | Explaining level changesDivision 3A: Redland Eagles v Keynsham (Tue 14 Oct 2014)Match played between Andy Gyles (home) and Kevin Ward (away).Match won by Andy Gyles. Result: 10-8,0-9,0-9,9-7,9-7. Starting level for Andy Gyles: 887, level confidence: 55%. Starting level for Kevin Ward: 1,564, level confidence: 43%. Kevin Ward to win as he is currently playing 76% better than Andy Gyles. Andy Gyles won 60% of the games and 41% of the points. This games result would be expected if he was better by around 10%. This points result would be expected if he was worse by around 21% (english scoring). These are weighted and combined to calculate that Andy Gyles played 3% better than Kevin Ward in this match. Assuming that any level changes are shared between both players, for this result it looks like Andy Gyles actually played at a level of 1,196 and Kevin Ward at a level of 1,160. Without any damping, both players would need to be adjusted by 35% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 25% and 25% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Andy Gyles changes to +20% and Kevin Ward changes to -25%. After applying standard match damping, the adjustment for Andy Gyles becomes +11.1% and for Kevin Ward becomes -11%. Apply match/event weighting of 75% for 'Mixed Autumn 2014/2015' so the adjustment for Andy Gyles is +8.3% and for Kevin Ward is -8.2%. 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 Kevin Ward 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. Andy Gyles: 74%, Kevin Ward: 66%. Reduce level confidence based on how unexpected the result is. Andy Gyles: 55%, Kevin Ward: 49%. 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 Andy Gyles: 963, level confidence: 55%. Final level for Kevin Ward: 1,493, level confidence: 49%. Notes
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