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Login: | Explaining level changesAngus Mackinnon v Jacqui Clinch (Sun 26 Mar 2017)Match won by Angus Mackinnon. Result: 9-4,9-5,9-4.Starting level for Angus Mackinnon: 370, level confidence: 83%. Set manually. Starting level for Jacqui Clinch: 463, level confidence: 74%. Set manually. Jacqui Clinch to win as she is currently playing 25% better than Angus Mackinnon. Angus Mackinnon 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 Angus Mackinnon played 50% better than Jacqui Clinch in this match. An upset! Assuming that any level changes are shared between both players, for this result it looks like Angus Mackinnon actually played at a level of 507 and Jacqui Clinch at a level of 338. 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 Angus Mackinnon changes to +29% and Jacqui Clinch changes to -33%. After applying standard match damping, the adjustment for Angus Mackinnon becomes +15.3% and for Jacqui Clinch becomes -17%. Apply match/event weighting of 50% for 'Redland Green Boxes' so the adjustment for Angus Mackinnon is +7.6% and for Jacqui Clinch is -7.8%. 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 Jacqui Clinch 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. Angus Mackinnon: 91%, Jacqui Clinch: 86%. Reduce level confidence based on how unexpected the result is. Angus Mackinnon: 66%, Jacqui Clinch: 63%. A final adjustment of +1.7% 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 Angus Mackinnon: 398, level confidence: 66%. Final level for Jacqui Clinch: 456, level confidence: 63%. Notes
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