I'm about the same height as Sampras, with similar ape-like build, one-handed BH and eastern FH. And the same size grip, 4 and 3/4. According to that grip size measurement technique, I ought to be using a 5 and 1/4. Yeah, that's a little much. A 4 and 7/8 would fit me best, I think. I do like the whip I get from the 'smaller' (4 and 3/4) grip I use, but I find what BP said is true if I demo a size 4. Feels like a pencil, not stable enough on BHs and volleys. I've shaken hands with Guga. He's about 3 inches taller than me and our hands are about the same size. He used a reeeally small grip, like a quarter or a 3/8 or something. Then you've got a bear like Boris Becker, with a fairly small paw for a big man, hence the small grip. And regular-sized guys like Mac and Pat Cash look like they use a big grip like a 4 and 5/8 or so. To each his own, of course. But to generalize...I believe the guys who come in a lot prefer a larger grip. The guys who use a one hander use a bigger grip, but if they go small (e.g. Guga), they use a more extreme BH grip. Don't know how Becker did it with that skinny li'l thang. Overall, though, it looks like the trend is toward larger guys with smaller grips.