The Maths
Each race will have a Number of Points Scored which varies based on the number of laps / finishers.
The total value of all the Fantasy Racers drivers participating in the race meeting gives us the Total Driver Value.
Using these 2 numbers the expected points per 1.0m of cost can be calculated (PPM) by dividing the Number of Points Scored by the Total Driver Value.
Using Abu Dhabi 2021 as an example, the Total Driver Value of all 20 drivers was 182.92. The Number of Points Scored was 2143. The expected PPM was 11.72.
2143 / 182.92 = 11.72
Lewis Hamilton cost 19.99 going in to this race, so his expected score was 235.
19.99 * 11.72 = 234.19
Driver Value * PPM = Expected Score
Lewis only scored 188, so undershot his expected target and achieved a PPM of 9.4047, approx 19.73% less than expected. This % is divided by 10 and applied to his current cost.
19.99 * (-19.73% / 10) = -0.39.
Driver Value * (Percentage Difference / 10) = Driver Adjustment
Lewis Hamilton changed from 19.99 to 19.60
Max Verstappen cost 18.57 going in to this race, so his expected score was 218.
18.57 * 11.72 = 217.56
Max scored 358, so overshot his expected target and achieved a PPM of 19.2784, approx 64.55% more than expected. This % is divided by 10 and applied to his current cost.
18.57 * (64.55% / 10) = 1.19869 (rounded to 1.20) increase in value.
Max Verstappen changed from 18.57 to 19.77