Menu | Explaining level changesMike Guthrie v Roger Hornby (Sat 25 Mar 2023)Match won by Mike Guthrie. Result: 11-9,11-4,12-10.Starting level for Mike Guthrie: 1,242, level confidence: 73%. Set manually. Starting level for Roger Hornby: 1,561, level confidence: 63%. Roger Hornby to win as he is currently playing 26% better than Mike Guthrie. Mike Guthrie won all of the games and 60% 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 48% (PAR scoring). These are weighted and combined to calculate that Mike Guthrie played 50% better than Roger Hornby in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Mike Guthrie actually played at a level of 1,706 and Roger Hornby at a level of 1,136. Without any damping, both players would need to be adjusted by 37% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 33% and 33% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Mike Guthrie changes to +28% and Roger Hornby changes to -33%. After applying standard match damping, the adjustment for Mike Guthrie becomes +13.6% and for Roger Hornby becomes -14%. Apply match/event weighting of 50% for 'Redland Boxes' so the adjustment for Mike Guthrie is +6.8% and for Roger Hornby is -6.5%. 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 Roger Hornby 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. Mike Guthrie: 86%, Roger Hornby: 80%. Reduce level confidence based on how unexpected the result is. Mike Guthrie: 62%, Roger Hornby: 58%. 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 Mike Guthrie: 1,325, level confidence: 62%. Final level for Roger Hornby: 1,484, level confidence: 58%. Notes
|