I took it from Chinese forum. Jerzy has to at least make 4th round of Cincinnati and Toronto and Washington QF before US open to cover the points he earned in the same period last year. US open will be another major even for Jerzy ranking as he only need to defend 10 points. Before Paris Master, he has to do well on Shanghai Master. The good news is he didn't attain Shanghai Master and Toronto Roger Cup last year.
Thanks for posting WC.
You can figure out year end ranking by using the normal ranking and taking into account the points that need defending.
Or you can go by just adding up points starting at the beginning of the year.
Some may tell you that defending points have nothing to do with year end ranking but it does if you use the regular ranking to calculate the year end result.
So there are two ways then of calculating the probable year end ranking by using the race or the regular ranking.