For the multi-tabling regs, I have found that they often take extra time "counting outs." Example, I'm PFR and get called in the blinds, flop is T 6 5 (2 suited). He checks, I bet, and then you can almost see his brain trying to cope with the "outs vs. pot odds" problem. If blanks hit turn/river, I'm almost certainly ahead.

This (I think) is a phenomenon in 25nl and lower, where the regs may just be learning basic poker math, but idk if applies higher up.