He got 13 games off Federer, while Federer won 20. Therefore Hartfield is 65% as good as Federer. Federer has 7010 rankings points, 65% of 7010 is is 4556. So Hartfield is really number two in the world.
what a nice interpretation of the stats
dieog hartfield is in the early 2oo
but a good showing in qualies reaching main draw
can help his confidence & by the end of the clay season can reach 100+
he has potential