If you like your “we were robbed!” conspiracy theories served with a mountain of evidence, let me direct your attention to Rob Arthur of Baseball Prospectus.

On April 5, Arthur sounded the alarm bells that MLB was using juiced up balls this season, citing the lower drag coefficient on baseballs during the first few days of the season as evidence.

He wrote: It’s possible to measure the aerodynamics of the baseball using the pitch-tracking radars currently in place in each MLB ballpark. By calculating the loss of speed from when the pitch is released to when it crosses the plate, you can directly measure the drag coefficient on the baseball.

The balls this year had a lower drag coefficient, making them more aerodynamic, making them fly out of ballparks at a record rate. Several teams surpassed the old record of 267 home runs — including the Twins, who wound up with the absurd record of 307 homers.

Well, using the same methodology, Arthur is now telling us that the ball has changed again in the postseason. His BP article is behind a pay wall, but a lot of the details are in a series of tweets, including these two:

Air resistance in the playoffs has shot up to the highest level since 2016, causing fewer homers. Multiple lines of evidence suggest that the postseason baseball is totally different than the one used in the regular season. … The speed and magnitude of the change and the timing of it aligning so perfectly with the playoffs makes it much harder to believe this was a random manufacturing accident. In the past, drag has drifted around slowly during the course of the season, but this was massive & abrupt.

He asserts that the data suggests there have been 50% fewer home runs than expected so far in the postseason.

All of this comes on the heels of Commissioner Rob Manfred asserting in a late September interview that MLB needed to go back and take a look at the baseballs it was using because of all the home runs. But he also said at the time that a report from scientists would be available “shortly after the World Series.”

But Arthur’s data suggests the ball is already different, though the reason is unclear (one thing that isn’t a factor: October weather. Arthur debunked that notion). And since he has been at the forefront of this discussion, I tend to believe his data — even if the postseason baseballs were in fact made earlier in the year.

This, dear Twins fan, is where you come in. The mere notion that the postseason baseball is different is concerning.

Sure, if the ball is different every team has to deal with it. And the Yankees, who swept the Twins, hit 306 homers this season — just one fewer than Minnesota — and would have been adversely affected as well.

But still: If you get used to playing one way and build your team to match the expectation of home runs, is it really fair if the ball is different when the stakes are the highest in that season?

It also stands to reason that the Twins benefited more from the juiced ball than other teams (including the Yankees) since so many of their hitters made unexpected leaps in power — and would therefore suffer more if indeed the ball was dulled down in the playoffs.

Or, as Arthur puts it: Drag has a much more significant effect on the marginal home run cases, though–the balls between 20-70%ish home run probability. These just aren’t carrying like they used to.

Would Miguel Sano’s lineout in the sixth inning of Game 3 have carried over Aaron Judge’s head? Would Marwin Gonzalez’s deep flyout in the same inning cleared the wall for a home run if balls were behaving the same way they did in the regular season?


It’s not the reason the Twins lost the series (they were only out-homered 5-4). But if the ball really was different for some reason, it’s ammunition to be suspicious and probably even mad.

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