It is not decided at all, the ATP official database randomly chooses a tournament to count. When you query a database and two result have the same exact parameters as to the query, both results being equal, the order of the display will be random each time the query is run. In this case, the query is run each Monday (or maybe when a player's tournament selection changes).
I see. Thanks. So it is not only possible, but also reasonably likely that the selected among the two tournaments will change after a week(or more).
With Rafa playing Basel his Vina del Mar points will be added to his countable tournaments if he loses before SF, right?
But not because of him playing Basel. He has already fulfilled the 500 requirement with Barcelona, Acapulco, MC and Beijing. It's just a matter of last years zero-pointer being dropped.
The rankings aren't loading for me. :/
I'm using Safari...
You are supposed to open the link in Slasher's sig.