You're falling victim to the base rate fallacy here, sure the evidence isn't definitive but it is alarmingly close. The probability that his win rate is in fact

You're falling victim to the base rate fallacy here, sure the evidence isn't definitive but it is alarmingly close. The probability that his win rate is in fact ~1000bb/100 is effectively zero whereas even if there were only a single cheater on earth the base rate for that would be on the order of one in single digit billions.