Big C said:
Here's one I always have to look up, because I always think no way it really happened:
Against the Giants in 1966, the Braves' Tony Cloninger hit two grand slams in a single game. And Cloninger was their pitcher.
It is not uncommon for other pitchers to get 50% of that (the author's guideline), but that's as far as they will ever get.
I'm tempted to say this is a record that will never be broken, because the universal DH is coming.
However, you never know. Othani, or far off in the future, someone like Ohtani, might pitch in a game where his manager decides not to use the DH. So even though the universal DH is almost certainly coming this year, it is still POSSIBLE for Cloninger to be matched, but astoundingly unlikely.
Cloninger was not only the first (and only) pitcher to hit 2 slams in a game, he was the first NL player to hit two slams in a game. No NL player did it again until Tatis hit his 2 in one inning. The NL is now at 3, to 10 for the AL.
If you want to look up something else related to 2 slams in a game that there's no way happened, Nomar was the 11th of the 13 MLB players to hit 2 slams in an inning, a couple of weeks after the Tatis 2 in one inning, and the first (and still only) player to do it at home. When Tatis hit his two, all 10 had been done on the road? Really? There is some advantage to hitting at home, so it should be a little more likely to happen at home. How do we have 12 out of 13 players who have done this on the road, and the first 10? Candlestick was a pitcher friendly park, but who knew that meant friendly to a pitcher hitting two grand slams?
4 years after Nomar as a Red Sox player became the only one to hit 2 slams at home, Bill Mueller as a Red Sox player became the only one to hit a slam from each side of the plate in the same game.
The 1998 2 slam day by Chris Hoiles is the only time a catcher did it.
So at least five guys who hit 2 slams in a game also have a feat nobody else accomplished - Cloninger the only pitcher, Hoiles the only catcher, Tatis the only two in one inning, Mueller the only from two sides of the plate, and Nomar the only one at home. You'd think Nomar would most likely be the first among that group to have someone else join him, but who knows.