What makes a great performance to you?

[Bond18]

When i watch a movie, i tend to get caught up pretty easy. I don't really sit there thinking about what kind of decisions the actors make or didn't make.

I can tell when i see a REALLY bad performance (which is obvious to everyone) and i can sometimes tell when someone gives an amazing performance, but still not often. This all despite being a theater major (in fairness, i was just looking for an easy one that let me play poker.)

So what makes a really great (or bad) performance to you? How do you evaluate? What do you look for? Other thoughts?