|
Menu
Login: | Explaining level changesDivision 2: Thornbury B v Lansdown 3 (Wed 21 Dec 2022)Match played between Ian Johnson (home) and Alisdair Wriglesworth (away).Match won by Alisdair Wriglesworth. Result: 14-16,15-8,12-15,15-8,15-17:8-15,7-15,13-15:12-15,7-15,7-15:15-11,10-15,11-15,10-15:9-15,15-17,9-15. Starting level for Ian Johnson: 1,835, level confidence: 72%. Set manually. Starting level for Alisdair Wriglesworth: 2,568, level confidence: 74%. Set manually. Alisdair Wriglesworth to win as he is currently playing 40% better than Ian Johnson. Alisdair Wriglesworth won 60% of the games and 47% 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 11% (PAR scoring). These are weighted and combined to calculate that Alisdair Wriglesworth played 5% better than Ian Johnson in this match. As Alisdair Wriglesworth has played below his allowed range at 2,138, his level reduction is 10.9% before damping. On the assumption that Alisdair Wriglesworth would normally have been playing at level 2,478 (based on typical behaviour), Ian Johnson played better than expected and therefore gains a pre-damping level increase of 13%. Allowing for the difference in level between the players, the adjustments have been reduced to 9.1% and 11% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Alisdair Wriglesworth changes to -8.8% and Ian Johnson changes to +11%. After applying standard match damping, the adjustment for Alisdair Wriglesworth becomes -4.2% and for Ian Johnson becomes +5.5%. Apply match/event weighting of 75% for 'Mixed Autumn 2022/2023' so the adjustment for Alisdair Wriglesworth is -3.1% and for Ian Johnson is +4.1%. Increase level confidence due to one more match played. Alisdair Wriglesworth: 86%, Ian Johnson: 85%. Reduce level confidence based on how unexpected the result is. Alisdair Wriglesworth: 74%, Ian Johnson: 73%. A final adjustment of +0.6% 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 Ian Johnson: 1,908, level confidence: 73%. Final level for Alisdair Wriglesworth: 2,525, level confidence: 74%. Notes
|