There was a time when there were known pros and unknown pros. The unknown pros, as in not known to the general public, substantially outnumbered the pros. I knew many of these guys over the years, most always open for any hustle not just pool. Most had a passing acquaintance with the gray bar hotel, local and county more than state and federal level.
I was a one trick pony myself, I played pool. I could take anyone that came through the door on a given night, I could lose too. As the other local unknowns soon learned, I won a lot more than I lost. Pool was for fun most of the time, the money wasn't important. A few times I was out of work for months, I made a living at pool, never a late payment or bill I am proud to say. However having to meet a daily or weekly nut took a lot of fun out of pool and I was glad to go back to work when a day job came along. I never considered myself a professional even when making a living at pool. Pool was in such poor shape I didn't consider anyone a pro pool player.
Today I would say anyone that plays in most of the larger pro events is a pro or aspiring pro. Most hopefuls don't make it to true pro's. That takes skill, luck, and marketability. Without luck and marketability you have to be able to beat the world's top dozen as often as not. In 1973 or so I considered going pro. To do that without a big chunk of my earnings coming from gambling I figured I would have to be in the top six or eight in the US, which meant in the world at that time. I didn't like my odds!
Hu