I got into the martial arts as a result of getting stabbed twice one night, robbed and nearly killed. At that point in my life (23 years old) I had already been stuck up at gun point 3 times so I knew the "world" could be a dangerous place.
I ran CJ's Billiard Palace and Carsons LIVE for 19 years and took part in breaking up probably 20-30 fights of different magnitudes. I'm not sure how, but I never got hit and got through that part of my life unscathed, even though I had to "subdue" a few people in different ways.
Martial Arts taught me a lot about the body and how it moves and coordinates through weapons movements. Pool, to me is like a martial arts form and I am more particular than many instuctors about feet position, arm/shoulder/wrist positions and how to set them properly in the pre shot routine.
I have a "connection calibration" technique that is directly from martial arts to make sure every part of your body connects to the "Line of the Shot". My objective as a player is to become a pool playing machine and to do this it requires an educated understanding of body mechanics.
This is one part of pool thats much better now compared to the 70's and 80's. One guy I use to run with seemed to like the worst dives in a state to gamble at. Back then bars was where the gambling was. A certain part of Chattonooga was famous for robbing pool players.