|
Menu
Login: | Explaining level changesPremier C: Lansdown 2 v Workout Harbourside (Wed 15 Mar 2017)Match played between Tim Brooksbank (home) and Martyn Ibson (away).Match won by Tim Brooksbank. Result: 9-4,9-6,9-3. Starting level for Tim Brooksbank: 1,675, level confidence: 59%. Starting level for Martyn Ibson: 2,176, level confidence: 71%. Set manually. Martyn Ibson to win as he is currently playing 30% better than Tim Brooksbank. Tim Brooksbank won all of the games and 68% 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% (english scoring). These are weighted and combined to calculate that Tim Brooksbank played 50% better than Martyn Ibson in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Tim Brooksbank actually played at a level of 2,341 and Martyn Ibson at a level of 1,557. Without any damping, both players would need to be adjusted by 40% to match this result. Allowing for the difference in level between the players, the adjustments have been reduced to 34% and 34% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Tim Brooksbank changes to +34% and Martyn Ibson changes to -27%. After applying standard match damping, the adjustment for Tim Brooksbank becomes +14.1% and for Martyn Ibson becomes -10.5%. Apply match/event weighting of 75% for 'Mixed Spring 2016/2017' so the adjustment for Tim Brooksbank is +10.6% and for Martyn Ibson is -7.7%. 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 Tim Brooksbank is limited to +10% and Martyn Ibson 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. Tim Brooksbank: 77%, Martyn Ibson: 84%. Reduce level confidence based on how unexpected the result is. Tim Brooksbank: 55%, Martyn Ibson: 60%. A final adjustment of -0.3% 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 Tim Brooksbank: 1,835, level confidence: 55%. Final level for Martyn Ibson: 2,069, level confidence: 60%. Notes
|