It is my experience from working in the sports betting industry for several years, including the risk reporting and risk managing part. In fact I'm pretty sure several people lived comfortable life by going around our risk management by using a loophole that was possible at the time in our country - it was possible to bet anonymously in person. So while we could limit maximum winnings per bet, we could not tie particular bets to persons, and they just placed several bets in different locations, or they used helpers.

I'm not going into speculations how they acquired the knowledge. Some people are just nerds, others sit at the stadiums and place bets right from there etc., but I'm pretty confident there are customers who are able to make money on sport bets and are not fraudsters.

I'm not sure if you'd discount that as obviously thats completely different than 1 person sitting in their bedroom placing bets but just thought I'd raise it incase this level of sports betting interests you.

From what I understand they place their bets in Asian markets rather than the markets consumers in the west would.