|
Menu
Login: | Explaining level changesDivision 2: University of Bath Ladies A v David Lloyd A (Thu 06 Nov 2014)Match played between Alice Richards (home) and Nicky Leeson (away).Match won by Alice Richards. Result: 9-2,9-1,9-2:6-9,9-4,9-5,9-10,9-3:7-9,9-3,9-2,3-9,6-9:2-9,6-9,1-9:3-9,0-9,6-9. Starting level for Alice Richards: 646, level confidence: 35%. Starting level for Nicky Leeson: 445, level confidence: 24%. Alice Richards to win as she is currently playing 45% better than Nicky Leeson. Alice Richards won all of the games and 84% 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 134% (english scoring). These are weighted and combined to calculate that Alice Richards played 134% better than Nicky Leeson in this match. Assuming that any level changes are shared between both players, for this result it looks like Alice Richards actually played at a level of 820 and Nicky Leeson at a level of 351. Without any damping, both players would need to be adjusted by 27% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 22% and 22% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Alice Richards changes to +15% and Nicky Leeson changes to -22%. After applying standard match damping, the adjustment for Alice Richards becomes +8.8% and for Nicky Leeson becomes -12%. Apply match/event weighting of 75% for 'Womens Ladies Winter 2014/2015' so the adjustment for Alice Richards is +6.6% and for Nicky Leeson is -8.8%. 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 Nicky Leeson is limited to -7.6% 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. Alice Richards: 59%, Nicky Leeson: 48%. Reduce level confidence based on how unexpected the result is. Alice Richards: 46%, Nicky Leeson: 38%. A final adjustment of -1.5% 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 Alice Richards: 670, level confidence: 46%. Final level for Nicky Leeson: 413, level confidence: 38%. Notes
|