is this the first wimbledon you will watch ? as for the formula, you need to add 100% points earned by a player on grass over the past 12 months but also 75% of the points in the 12 months before that - Nadal did not play any grass tournament last year.
no its actually just 75% of the points for the best ONE grass tournament result from 2 years ago
so Rafa is only getting his 2008 wimbledon victory - 2000 x 0.75 = 1500 points
Roger is around 1500 points ahead of Rafa after the formula as he has 2000 points from 2009 and 900 points from 2008 (1200 x 0.75 = 900)