Slasher you could just add 3 columns. 1 for a country ranking next to a country column or official ranking (that shouh be easy, not sorting the list or anything, just adding 1 extra number by counting players from that country allrdy listed-higher ranked and adding 1) and at the end of the list (like that GB forums has) you count add 2 columns for ATP Race ranking and ATP race points... I realise that would be like making anouther rankings and making a new (similar, but a little different) algoritam but only for players with commitment, for the rest just add points from this year. For players with commitment you would need to count if they didn't furfill the commitment (regarding the ATP500 and 250) and count 4 ATP500s and 2 250s (and possible challengers) and when they furfill it, you count the best 6 tournaments. I mention that bcs I don't like the way http://live-tennis.eu/race
just adds points dissregarding the mandatory tournaments that will surely replace added points. At makes a player actually lose YTD points by playing a mandatory tournament.
I realise you don't need any explaining as you know about this stuff more than I do, but I just wanted to make myself clear about what I'm talkin about. Anyway, it's just a suggestion, you are doing a great job as of now!