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Login: | Explaining level changesJames Trevelyan v Sarah Trevelyan (Mon 09 Sep 2024)Match won by Sarah Trevelyan. Result: 16-18,15-10,7-15,15-11,11-15.Starting level for James Trevelyan: 269, level confidence: 66%. Starting level for Sarah Trevelyan: 661, level confidence: 54%. Sarah Trevelyan to win as she is currently playing 146% better than James Trevelyan. Sarah Trevelyan won 60% of the games and 52% of the points. This games result would be expected if she was better by around 10%. This points result would be expected if she was better by around 8% (PAR scoring). These are weighted and combined to calculate that Sarah Trevelyan played 9% better than James Trevelyan in this match. Due to the difference between the players' levels, allow for the likelihood that Sarah Trevelyan was taking it easy by anything up to 18%. This gives her an allowed level range for this match between 401 and 661 without affecting her level. As Sarah Trevelyan has played below her allowed range at 344, her level reduction is 17% before damping. On the assumption that Sarah Trevelyan would normally have been playing at level 541 (based on typical behaviour), James Trevelyan played better than expected and therefore gains a pre-damping level increase of 36%. Allowing for the difference in level between the players, including some additional protection for the better player, the adjustments have been reduced to 5.5% and 21% respectively. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Sarah Trevelyan changes to -5.5% and James Trevelyan changes to +18%. After applying standard match damping, the adjustment for Sarah Trevelyan becomes -4.3% and for James Trevelyan becomes +10.1%. Apply match/event weighting of 50% for 'Westbury David Lloyd Boxes' so the adjustment for Sarah Trevelyan is -2.1% and for James Trevelyan is +5.1%. Increase level confidence due to one more match played. Sarah Trevelyan: 74%, James Trevelyan: 81%. Reduce level confidence based on how unexpected the result is. Sarah Trevelyan: 49%, James Trevelyan: 54%. A final adjustment of +0.7% 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 James Trevelyan: 283, level confidence: 54%. Final level for Sarah Trevelyan: 656, level confidence: 49%. Notes
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