What would be

[pgellis]

Originally Posted by pitchernut

I'd go along with the notion that a no-no is to a pitcher what hitting the cycle is to a batter.

So a perfect game would be the equivalent of hitting 4 home runs in one game?

Again, according to Wikipedia, there have been:

20 Perfect Games in MLB History
and
15 Players that have hit 4 HRs in a single game.

I'd say that that is pretty equivalent.