I've never actually been in a fight at a poolroom, but I've seen plenty. I live in Los Angeles, the gang capital of the world. I was at one poolroom in a rougher part of town, and a fight between two asian gangs broke out. I grabbed my girlfriend and we ran out the back door. Moments later we heard gunshots. Turned out two gang members were killed, one was shot point blank in the face.
One time I was at another poolroom, this one dominated by a particular asian gang, and there was this scary looking fellow who had tattoes from head to toe, even on his face. He played this one chump for money, some wealthy-looking persian fellow, and he beat him for about $500. The wealthy-looking guy said he didn't have the money on him, and that he would have to go to the ATM to get the money. The gang member told him he had better come back, and since they both kind of knew each other, the wealthy looking guy gave the gang member all he had on him, I think about $200, and said he was off to the ATM. The guy didn't come back that night. In fact, he didn't come back for 6 months. I was in there that particular night when he did come back. He walked in, looking around, and saw the tattoed gang member approaching him. The persian guy waved to him, and all of a sudden I saw a handaxe flying towards the guy. The persian guy ducked out of the way, and got on his knees and started begging the gang member not to kill him. He said that he had come to give him his money finally, and the reason he did not come back for 6 months because when he was on his way to the ATM, he got pulled over and searched and was arrested for drug posession and DUI. Funny thing is the persian guy continued to come around and lose more and more money to the guy, and later they became friendly.
I was at a poolroom near my house and witnessed two latino gangs get in a rumble, even the girls that were with them were in the fight. Later that night one of the gangs came back and shot up the place as they drove by, since they were mad that the bouncers broke up the fight and called the cops.