Correct me if I'm wrong, but I'm pretty sure the 92% refers to an A, B, C system. Say you bet 100 and lose, then the next wager is double, at 200. If that loses, you bet 400 on the 3rd bet. So to lose the system play, you would need to lose 3 in a row. Obviously, it's much easier to hit 92% doing something like this, which is probably why he posts his standard record at 58%.
I really don't have any dog in the fight, but he seems like a good soccer capper, and we don't have a ton of that here, so whether or not you like these Martingale-like systems, I'm glad he's around posting some soccer opinions. BOL to everyone today.