Most dominant no hitter in MLB history? Ryan had a couple of no hitters with 16 and 17 Ks, respectively. But he of course had walks. Hanley with an error in the 7th on a fairly routine grounder he rushed and threw badly to first.
15 Ks would have been the most ever for a perfect game So yeah, kinda If only that ball wasn't mishanleyed.
It may be anyway, even with the error. As mentioned, it doesn't take away from the pitching, but a runner reached base, so there's no perfect game.