Well, I do not know what kind of gambling platform you are talking about but I am pretty sure that there are too many sites you can try and can validate the fairness of the gambling site.
There are many gambling site to start with and this is why the best thing to do is to start looking first the best gambling platform. I bet the most stable gambling platform are those platform promoted here in the forum. This is an assurance because most of the gambling sites here are been operating for some time.
I think there are still some gambling places that still can't be fair because usually the fair possibility posts are only on or in front of the gambling site's website but sometimes they insert an encryption script that makes enemies often lose.