32 teams in the NFL, 15-16 games a week.
There’s approx. 240 different possible outcomes each week, chances that you land on the correct one twice in a row is near impossible.
So you wouldn’t be conning anyone, unless you were picking only one game each week, in which case you have a 50% chance and therefore no one would care if you got it right twice, an octopus can do that.
Further to the above, the sports gambling industry is huge, chances that you can offer something over and above what multi-million dollar betting agencies can offer is frankly absurd unless you’re an MIT Maths grad.
So just the stock market then?