I have heard that the Tennis Leagues "4.5 division" is meant for high level USTA 3.5s and 4.0s. I would assume you'd fit in better w/ the 5.0 division but I don't know anyone who's played in that division so can't be certain.
When you do USTA flex singles, I'd stick w/ the 4.5. There aren't many 5.0 leagues anyway in this area anyway.
When you do USTA flex singles, I'd stick w/ the 4.5. There aren't many 5.0 leagues anyway in this area anyway.