How MLB’s baseball meddling is affecting the ALCS

A player’s critique of human strike zones is often a plea for consistency. Players seldom call out a bad game from a home plate umpire, but rather refrain that they want to see the same pitch called the same way an entire game. A ball called a strike is less of a problem within a particular game if the same pitch is called a strike in every inning.

In a lot of ways, I think that’s how players and teams feel about the baseball this October too. Baseball Prospectus has done pretty solid research that indicates the baseball is behaving differently this postseason, FanGraphs writer Devan Fink has perhaps the best analysis showing that exit velocity, launch angle and xwOBA are almost identical to the regular season despite fewer balls leaving the park, and even the players themselves smell something funny:

The one piece of evidence that sticks the most with me is when Cardinals manager Mike Schildt let us sneak a peek behind the curtain at internal analysis of the baseball:

“Our front-office analytical group is saying the ball’s not traveling at about a 4½-foot difference.”

It’s so rare to get nods from front office research, certainly the most robust in the game, like this, and if teams know that something is wonky with the ball, that’s good enough for me to accept. It’s also worth noting that the BP article linked above controls for changes in temperature - it’s not the cold weather preventing home runs.

So the ball is different, again, and this time seems to not be carrying as far. For both teams in the ALCS, that’s going to mandate a change in approach. For the Yankees, this is good news for their best postseason starter, Masahiro Tanaka. The right-hander struggled all year to find a way to replace his splitter; the lower seams on the baseballs used all summer meant the ball wouldn’t break quite the same way.

In October, Tanaka’s been his usual sparkling self - 11 IP and just one run allowed. Crucially though, he has thrown that splitter 51 times out of 151 total pitches, a 33.7% rate. Compare that to the 26.9% rate he threw the split in the regular season, and it’s clear that something has raised his confidence in that pitch. I’m willing to bet the higher seams are back, Tanaka knows that, and he’s throwing the splitter more.

On the other hand, the Astros probably do get a little harder to beat. Justin Verlander came into the series with one weakness - his contact allowed tends to be in the air, and he gave up 36 home runs in 2019, a career high. On Sunday, the Yankees tagged him for a lot of loud contact, 10 batted balls hit at least 95 mph off the bat. Seven of those were in that sweet spot between 15-35 degrees of launch angle, where you really see damage. And yet, the only significant blow to Verlander was the home run by Aaron Judge, a guy who doesn’t need special baseballs to hit for extreme power.

Other Yankees did benefit a lot from the juiced ball this year - DJ LeMahieu almost doubled his previous career HR high and HR/FB rate, Didi Gregorius and Brett Gardner have always owed a lot of their power to funky baseballs, and the guy who led the team in HRs this year, Gleyber Torres, hit for far more power in his sophomore season than any scouting report could have projected.

If the ball is in fact different, it lowers the difficulty of facing a lineup that used to boast power from all nine positions. One of the fun parts about watching this year’s Yankee team was the idea that anyone, 1-9, could come up with a big hit when needed. If there’s a power drain in the postseason, that chance declines pretty significantly.

I don’t think this would be such an issue if the ball had been performing in July the same way it is in October. Like the strike zone, the push is for consistency, not necessarily correctness.