for me i based NTRP on players i can beat. I can keep it very competitive with my Division 3 college tennis friend. usually our matches end up with scorelines such as 6-4 7-6 or something of that sort.
While playing my Division I college tennis friend (one of the less prestigious ones) can straight set me pretty easily 6-2 6-1 ish.
Wimbledon 2004 Final. The fearless, hard hitting, fiery young 21 year old Andy Roddick.