Hey I just got the same question by mail also.:) So I copy my answer:
"I remember getting some good info long ago that for Offensive Flow (which of course is vital for creating good scoring chances --> shooting %), Handling for PG is most important, but also Passing for SG,PG,SF,PF,C (about in that order), AND Handling for SF..! It may even read in the game manual something about HN for SF if I remember correctly..?
regards, /DM"
Quite vague but anyway.:)
!zazhigai!