Bottom line is, getting into a fight nowadays, especially at a bar, is like playing Russian roulette.
Wisdom would dictate that when not knowing the background of who you’re dealing with, restraint is usually the best course of action, unless having to defend yourself or family/friends from a physical/violent attack.
One of my good buddies used to be Secret Service detail for the Obama’s. I never knew it until one of our mutual friends told me one day. He is the most down to earth, chilled dude, so you would never guess that he’s a trained killer.
I asked him about it one day, and he nonchalantly told me that it was no big deal. He doesn’t look like he could hurt a fly. But as the saying goes, don’t judge a book by its cover.