Mexico City Series Provided an Elevated Run (and Entertainment) Environment

“What poor sucker is going to have to pitch in those games?” That’s what Meg Rowley asked last year on an episode of Effectively Wild after MLB announced a two-game series between the Giants and Padres in Mexico City. Those games happened over the weekend, and they lived up to those lofty expectations. Played at an elevation of 7,349 feet — more than 2,000 feet higher than Coors Field, in case you hadn’t been told several times already — they featured 15 home runs, including 11 in Saturday night’s 16–11 offensive explosion. Although Sunday’s game started with yet another home run, this time courtesy of LaMonte Wade Jr., the wind was blowing in, accounting for the paltry total of five homers. So far in the 2023 season, the average game has featured 2.26 home runs. By my calculations, that’s a whole lot less than 7.5 home runs per game. It was so wild that Nelson Cruz hit a triple yesterday. Let me rephrase that: The very nearly 43-year-old Nelson Cruz hit a stand-up triple yesterday. This was not baseball as usual.

All the same, it was extremely fun baseball. Robert Orr of Baseball Prospectus put it best, tweeting, “The game is being played on the surface of the moon.” The ball moved differently out of the pitcher’s hand, off the bat, and coming off the turf. In this article, I’ll be relying on Statcast data, so I should note up front that the stadium was working with a temporary TrackMan setup, rather than the permanent Hawkeye systems installed in all 30 MLB parks. It’s reasonable to expect that the numbers are not quite as reliable as they normally would be, but they’re still plenty convincing.

Brandon Crawford, who is younger than Nelson Cruz but still old enough to pique the interest of an actuary, hit the longest home run of the series. After jogging around the bases on a home run that was eventually ruled foul on video replay, he hit a 482-foot blast, tied for the second-longest home run of the season with a Jarred Kelenic blast that came off the bat six miles per hour faster; Crawford’s home run was 105.7 mph, with a launch angle of 31 degrees.

I pulled data on every fly ball between 104–106 mph and 30–32 degrees in the Statcast era; the average ball within those parameters flew 415 feet. If you limit the dataset to just Coors field, the average ball went 444 feet, still 38 shorter than Crawford’s. I did the same search for every fly ball or line drive with a launch angle over 10 degrees and an average exit velocity 85 mph or faster. On average, those 41 air balls traveled 29.2 feet farther than you’d expect them to in an MLB park, and 11.7 feet farther than you’d expect them to at Coors — a massive difference.

Because the wind was blowing in on Sunday, the numbers were actually very different on the two days: 39.7 extra feet on Saturday, compared to 15.8 on Sunday. In all, popups, line drives and flyballs had an expected batting average of .443 and an actual batting average of .574. “You can see hitters are salivating up there,” said Blake Sabol after the first game.

Making things worse (or better, depending on your point of view) is what Susan Slusser of the San Francisco Chronicle tweeted: “I learned after the game that the humidor here is NOT set at Colorado levels or lower. It’s set at the same 70 degrees and 57 percent humidity as the 29 not-Colorado parks. ‘That’s a joke,’ one member of the Giants traveling party said.” MLB didn’t actually have many options on that front, though. As Ben Lindbergh noted in 2017, “In Mexico City, the relative humidity during the summer months is considerably higher than 50 percent, so if a team were to store baseballs in the same conditions that the Rockies do at Coors, the balls would dry out and fly farther.” MLB couldn’t compensate by increasing the humidity even further, because the extra moisture would make the baseballs too heavy. Nobody said playing baseball on the moon would be simple.

With all that in mind, you might have come into the game assuming the plan for each defense was just to keep the ball on the ground, in which case the playing surface of Estadio Alfredo Harp Helú had a surprise for you. Michael Baumann documented in January that artificial fields often play fast, but this was something else entirely. The ball absolutely jumped off the turf. The fielders had their work cut out for them reading hops, and the bounces in the outfield were sometimes jarring to watch.

Grounders skipped right through the infield, and choppers took mountainous bounces in front of the plate. Over the two games, the 48 groundballs hit had an expected batting average of .208 and an actual batting average of .375.

The thin air also had an effect on the pitches. I pulled all of the available Statcast data for every pitcher and compared it to their season average for that pitch type. As you’d expect considering the low-drag environment, the spin rate for the average pitch was up 63.7 rpm, with 2.9 inches less horizontal break and 2.2 inches less vertical break. Separating pitches that rise and sink (after accounting for the effect of gravity), rising pitches lost 2.4 inches of ride, whereas sinking pitches lost 1.2 inches of drop. But the reduced movement didn’t keep pitchers from missing bats. So far this year, pitchers have a 12.1% whiff rate and are averaging 17.4 strikeouts a game. In Mexico City, the whiff rate was 14%, with 23.5 strikeouts per game.

All the same, you do have to feel for those poor suckers who had to pitch, especially on Saturday. Sunday’s starters, Alex Cobb and Yu Darvish, fared well. The latter made it through six innings on four earned runs; Statcast says he upped his slider and cutter rate and abandoned his sweeper, but that might just be the reduced movement fooling the pitch-tracking system. Cobb allowed three runs over five innings, relying more heavily on his curveball and de-emphasizing his splitter. “I threw a couple bullpens while I was out here,” he said after the game, and he reportedly brought a Trackman device into the bullpen. “The ball wasn’t moving very much. Just kind of showed up and fortunately I had enough stuff moving to at least get me through five.”

Saturday’s starters were not so lucky. Sean Manaea also threw on Friday to see how the thin air affected his pitches, but he ended up lasting just two innings on five earned runs and taking a hard line drive off the leg. Padres starter Joe Musgrove even spoke with a breathing coach before his start on Saturday, hoping to find a way to deal with the reduced oxygen levels. Unfortunately, he still allowed seven runs over just 3.1 frames.

In all, baseball in Mexico City was as advertised. The games were packed and exciting, and it seems like there are ways still on the table to tweak the elevated run environment. Even if humidor or other ball-related adjustments are out, it seems like it would make a difference playing on a field with larger dimensions, more foul territory, or a surface that bears less of a resemblance to a pinball machine. While the games were wild, they were often wild in a good way. I’ll definitely be excited for the next mountaintop series.