[Dire]

A check raise is rarely going to be an ace here. It's usually going to be a massively polarized range: bluffs or a monster. You need reads to determine if the guy is capable of bluffing flops like this, which more and more people are starting to do.

AF and preflop numbers are close to useless here. Some people bluff these flops habitually. Some never do. Their AF and preflop numbers aren't going to really help you figure it out.