A couple of things...
My post wasn't (necessarily) meant to compare how the game is played today vs. the past, and how Haddix's performance will never be duplicated. Rather, was this the greatest individual accomplishment over the course of a single game in the history of baseball? At the start of every one of the more than 210,000 games played, two players had the opportunity to pitch a perfect game. Only 23 have and Haddix's performance isn't one of them. Nobody has done it twice. Of the more than 420,000 opportunities less than .0055% have met the criteria for being "perfect." Had the Pirates pulled out a win in the bottom of the 12th, the Haddix sample would have represented .00024% of the universe of games.
Secondly, this wasn't even about just pitchers. It considers all players and everything that has happened. Is there a more astonishing accomplishment than 12 innings of perfect ball? Would, for example, a second baseman starting 9 triple plays in the same game register as a greater accomplishment? The earlier citation of Cloninger hitting 2 grand slams while pitching a complete game is a great example. Fewer players (13) have had multiple grand slam games than have pitched perfect games. No player has done so more than once. More players have played than have pitched, so there could have been, theoretically, more opportunities, but how many have there actually been? An opportunity is a player coming to the plate with the bases loaded multiple times during a game. How many times has that actually happened?
And I don't mean to make this all about statistics. Every oddity isn't some grand accomplishment. Can others cite an example they might rank above Haddix? Which is the greater accomplishment, Haddix's 12 innings or Don Larsen's World Series perfect game?
Anyway, thanks for all the responses.