Have a look here. I think Tyler Cowen's idea is better than the one he refers to, but I still think it's a solution waiting for a problem. Who gives a rat's behind about AlphaZero drawing 98% of its games with itself, when it will win 100% of its games with Magnus Carlsen? (Or at least 95% of them.) We humans make plenty of errors, even at the super-GM level, and in the quick games that dominate contemporary play decisive results are a commonplace.