EV (only when you suspect that you are behind in the hand)
Just as the title says: do you only calculate EV when you believe you are behind in the hand? If I had aces and for context, I'm HU with a Nit, the flop comes K39r. There would be no need there, right? But if I had JTs against that same Nit with the same flop, and he bet into me, THEN would be the perfect time to break out the EV equation, right? Or do I calculate EV every hand no matter what?