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Login: | Explaining level changesBecky McGillveray v Phil Swanson (Sat 20 Jan 2024)Match won by Becky McGillveray. Result: 15-13,15-10,15-9.Starting level for Becky McGillveray: 229, level confidence: 86%. Set manually. Starting level for Phil Swanson: 271, level confidence: 60%. Phil Swanson to win as he is currently playing 18% better than Becky McGillveray. Becky McGillveray won all of the games and 58% of the points. This games result would be expected if she was better by around 55% or more. This points result would be expected if she was better by around 41% (PAR scoring). These are weighted and combined to calculate that Becky McGillveray played 45% better than Phil Swanson in this match. Assuming that any level changes are shared between both players, for this result it looks like Becky McGillveray actually played at a level of 300 and Phil Swanson at a level of 207. Without any damping, both players would need to be adjusted by 31% to match this result. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Becky McGillveray changes to +20% and Phil Swanson changes to -28%. After applying standard match damping, the adjustment for Becky McGillveray becomes +11.1% and for Phil Swanson becomes -15%. Apply match/event weighting of 50% for 'Redland Green Boxes' so the adjustment for Becky McGillveray is +5.6% and for Phil Swanson is -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 Phil Swanson 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. Becky McGillveray: 93%, Phil Swanson: 78%. Reduce level confidence based on how unexpected the result is. Becky McGillveray: 71%, Phil Swanson: 59%. A final adjustment of -0.2% 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 Becky McGillveray: 241, level confidence: 71%. Final level for Phil Swanson: 258, level confidence: 59%. Notes
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