Laura Seaman v Karen Robins (Mon 22 Nov 2010)
Match won by Karen Robins. Result: 10-15,10-15,6-15.
Starting level for
Laura Seaman:
141, level confidence: 60%.
Starting level for
Karen Robins:
140, level confidence: 54%.
Laura Seaman to win as she is currently playing
1% better than Karen Robins.
Karen Robins won all of the games and 63% 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 73% (PAR scoring).
These are weighted and combined to calculate that Karen Robins played
73% better than Laura Seaman in this match.
Assuming that any level changes are shared between both players, for this result it looks like Karen Robins actually played at a level of
185 and Laura Seaman at a level of
107. Without any damping, both players would need to be adjusted by 32% 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 Karen Robins changes to +32% and Laura Seaman changes to -28%.
After applying standard match damping, the adjustment for Karen Robins becomes +16.6% and for Laura Seaman becomes -15%.
Apply match/event weighting of 75% for 'Hertfordshire League 2010/2011' so the adjustment for Karen Robins is +12% and for Laura Seaman is -10.8%.
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 Karen Robins is limited to +10% and Laura Seaman 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. Karen Robins: 74%, Laura Seaman: 77%. Reduce level confidence based on how unexpected the result is. Karen Robins: 56%, Laura Seaman: 59%.
Final level for Laura Seaman:
134, level confidence: 59%.
Final level for Karen Robins:
154, level confidence: 56%.