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...the next pick to the people who saw you pick the "winner". Now half of those people see one team, the other half see you pick the other team, and whoever saw you pick the winner thinks you've got a 100% accuracy rate over two games. You could do that for a while and then offer to sell your pick for the Superbowl. Starting with a big enough group in the beginning, this might be really lucrative.
But is it legal?
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.