<img src="http://i2.cdn.turner.com/nba/nba/multimedia/photo_gallery/1001/gameaction0112/images/1.jpg" alt="Stylish" width="460" height="520" hspace="40" vspace="40" align="left" border="0" />
assuming you're going for just "smooth" Arenas, no Duncan, no Harden, Mayo, Crawford--there are plenty better how about Peja when he was on the Kings? Monta? Jamison? Ray Allen (esp. pre-Boston)
I'm going to assume you fluidity, grace, elegance, polish, body control, and natural feel for the game. Kinda like how you would judge...women. Some people like Erin Andrews effortless charm over Jenny McCarthy's bold and brazen approach. Maybe I'm wrong, just trying to make some sense out of it.
Jamal Crawford definitely has rhythm. He's one of the best 1-on-1 players in the league. T-Mac in Orlando moved really well, that's why so many people liked his style of play. Ray Allen was pretty smooth, but not as complete as McGrady. Kobe kinda looks robotic. Wade is definitely a player who moves with rhythm
I think thats pretty much what he means. Thanks for helping explain what the OP means as opposed to just ridiculing him like other posters are because they dont understand him.