But first, a rough sense of the odds involved in Tatis Sr.'s epic inning (let's face it: with two grand slams, no one else has approached this apex of run production before or since). During the TV broadcast of this evening's Astros-Cubs game, Bob Costas brought up the odds of Tatis Sr's feat: he had it pegged at twelve million to one. (We await confirmation or correction for this estimate from long-time compatriot Brock Hanke...)
AND, as you might well suspect if you've been hanging out here for any significant amount of time, we have something else up our sleeve.
We went back into that "event finder," as noted earlier, and counted up the number of grand slam homers in each year. That took a bit of time, as the tool doesn't have a summarizing feature: you have to eyeball the yearly totals to calculate the number of homers per season...
The color-coded yearly cells represent seasons in which the record for most grand slam homers in a season was set (and re-set). With homers scarce in the last decade of the Deadball Era, you can figure that grand slam homers would be even more scarce, and so they were.
But the pace picks up soon enough: the yearly total passes 40 in 1929, exceeds 50 in 1940, pulls its own version of Maris besting the Babe (that's sixty-one homers, in case you've forgotten) in 1950, then pushes past that to 78 slams in the year Maris actually bested the Babe. The totals declined in the sixties, dropping down to 37 in the "year of the pitcher" but nearly doubling with expansion the following year.
The boom year of 1970 upped the record to 88, and it stayed there for awhile, pushing past it when things got rather sluggery in the mid-1980s. It hit the 100 mark in 1987, dipped a bit in response to the downturn in offense when the strike zone was recalibrated in 1988, and got revved up when the Offensive Explosion kicked in, setting records in back-to-back seasons in the mid-nineties for the first time in the 1920s.
The current record was set in 2000, and not even the "launch angle" gambit has managed to dislodge that season's total, though the sluggers in 2019 and 2021 came pretty close. The totals dropped down a bit in '22 and '23, and the early rate in '24 seems to be pretty much in line with those seasons.
Here you can see the ebb and flow of the grand slam frequency over time, as it builds up to an new peak (four per team per season) in the the Maris-Mantle year, then is cut more than half seven seasons later ("year of the pitcher," indeed).
It rises back over three in the seventies, peaks again in 1987, subsides for awhile before setting its records in the mid-nineties, with the apex (5.9 grand slams per team per season) coming in 2000. It has never reached such heady heights again, though it's gotten back over five on two occasions, the homer-happy years of 2019 and 2021.
SO there you have it--a "big data" glimpse at the bases-loaded homer. We're betting that you didn't think the yearly totals had gotten so high, though they've leveled off a good bit since the "homer heyday" period in the decade of the 2000s.
But don't bother to bet on someone following in Fernando Tatis Sr.'s footsteps anytime soon. And don't figure on it happening again with one further wrinkle that most if not all have forgotten: Tatis Sr. hit both grand slams in that third inning twenty-five years ago against the same pitcher! Take a dive and take a bow simultaneously, Chan Ho Park--what a way to get in the record books for keeps...
