You become a regular at the lowbrow dive of a bar, Tanks, dark joint,cheap shots...sort of smells like puke and urine.
You gradually learn who comes in with cash now and then, the binge drinkers, mollikins generally.
These are the guys you watch, these are the muggers.
Poor wretched alcoholics that have to rob pedestrians to ease their liquor pains...
But we both know You and I, that you know they are an easy target to mug and you deserve that money. These losers would drink themselves to death if you didn't take this money off them on a regular basis. Generally weak, drunk and with no recourse to the law at all. So you follow them out and watch them commit their crime and then trail them on their way to the bar. Knock them out cold from behind and take their money. You hit this one skrull and he was holding three thousand bucks, you sort of had to break his skull as he was so intent on hanging on to this money...
You are back in the bar after hitting the card room on your way over to see if you could come up with a quick win on a few bucks to drink up without anyone seeing that you were suddenly in the money.