Lol there is no such thing has truly fair betting. You could use random.org, but their numbers are based on results of a physical anomaly, which is not totally fair.
The best thing atm is probably fair, which has been documented many times.
I don't know what you're trying to say. If both the site and the player have no way to determine the result before it is shown, then it is fair. Using random.org is fair, but no one wants to use that because people in this bitcoin world want provably fair.
Probably fair is not something anyone wants. The probabilities are there, but you want it proven beyond doubt.
I think what he's trying to say is not that nothing is probably fair, but nothing is 100% fair and random. A formula will always be restricted by parameters.