Mechanical Turkers paid $1 are better at predicting recidivism than secret, private-sector algorithms

Going by scientific definition, what’s the threshold (statistically speaking) to consider something being better than random chance? Tried searching it but i wasn’t sure how to properly word my question.

I would assume a coin flip is 50-50, so a piece of software being 65% could arguably say that it’s better than a coin flip. I’m not making that argument myself, but i was just curious why a 65% accuracy is acceptable… maybe it isn’t but then what percentage would be the threshold for acceptable?