Menu | Explaining level changesChris Berke v Marcia Brittain (Wed 10 Apr 2024)Match won by Chris Berke. Result: 15-1,15-4,15-6.Starting level for Chris Berke: 804, level confidence: 70%. Starting level for Marcia Brittain: 1,097, level confidence: 10%. Marcia Brittain to win as she is currently playing 36% better than Chris Berke. Chris Berke won all of the games and 80% of the points. This games result would be expected if he was better by around 55% or more. This points result would be expected if he was better by around 309% (PAR scoring). These are weighted and combined to calculate that Chris Berke played 309% better than Marcia Brittain in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Chris Berke actually played at a level of 1,900 and Marcia Brittain at a level of 464. Without any damping, both players would need to be adjusted by 136% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 109% and 107% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Chris Berke changes to +16% and Marcia Brittain changes to -107%. After applying standard match damping, the adjustment for Chris Berke becomes +9.1% and for Marcia Brittain becomes -44%. Apply match/event weighting of 50% for 'Limpsfield Leagues' so the adjustment for Chris Berke is +4.5% and for Marcia Brittain is -18%. 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 Marcia Brittain is limited to -9.6% 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. Chris Berke: 84%, Marcia Brittain: 32%. Reduce level confidence based on how unexpected the result is. Chris Berke: 35%, Marcia Brittain: 13%. 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 Chris Berke: 839, level confidence: 35%. Final level for Marcia Brittain: 1,000, level confidence: 13%. Notes
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