|
Menu
Login: | Explaining level changesDivision 2C: University of Bristol Sharks v Whitchurch Imperial (Tue 13 Mar 2012)Match played between Ali Ladak (home) and Richard Lay (away).Match won by Ali Ladak. Result: 9-6,9-2,9-1. Starting level for Ali Ladak: 1,234, level confidence: 64%. Starting level for Richard Lay: 980, level confidence: 76%. Set manually. Ali Ladak to win as he is currently playing 26% better than Richard Lay. Ali Ladak won all of the games and 75% 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 76% (english scoring). These are weighted and combined to calculate that Ali Ladak played 76% better than Richard Lay in this match. Assuming that any level changes are shared between both players, for this result it looks like Ali Ladak actually played at a level of 1,459 and Richard Lay at a level of 829. Without any damping, both players would need to be adjusted by 18% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 16% and 16% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Ali Ladak changes to +16% and Richard Lay changes to -13%. After applying standard match damping, the adjustment for Ali Ladak becomes +8.5% and for Richard Lay becomes -8%. Apply match/event weighting of 75% for 'Mixed Spring 2012' so the adjustment for Ali Ladak is +6.4% and for Richard Lay is -5.9%. 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 Richard Lay 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. Ali Ladak: 80%, Richard Lay: 87%. Reduce level confidence based on how unexpected the result is. Ali Ladak: 68%, Richard Lay: 74%. A final adjustment of -0.1% 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 Ali Ladak: 1,311, level confidence: 68%. Final level for Richard Lay: 932, level confidence: 74%. Notes
|