Blisters and the New Ball

Talk to pitchers on the record, and the links they’re willing to draw between an increase in blisters and what looks like a tighter baseball are minimal. That makes sense — and it’s doesn’t seem to be concern for politics or press relations that’s holding them back. There are so many confounding factors that it’s the probably the right way to approach the situation.

Talk to a few pitchers off the record, though, and another link emerges, one that might provide some insight into the relationship between seams and blisters.

We first heard about the blister epidemic from Marcus Stroman, in typical brash fashion. Mike Fitzpatrick at the National Post had the quote:

“I feel like it’s an epidemic that’s happening across the big leagues now, a bunch of pitchers getting blisters, guys who have never had blisters before. So for MLB to turn their back to it, I think that’s kind of crazy,” the Toronto Blue Jays right-hander said. “I have no theory. But obviously, I mean, it’s not a coincidence that it’s happening to so many guys all of a sudden. It’s not a coincidence.”

He seems to be pointing the finger at the ball, and that makes a little sense. Rob Arthur at FiveThirtyEight found that the seams on the ball must be lower because the coefficient of drag on pitched balls has been going down. And if you graph that coefficient (provided by Arthur) against blister days lost (divided by calendar days, and provided thanks to Mike Sonne), you see one go down as the other goes up.

That’s a three-month rolling “days missed” metric for blisters. It reveals an explosion of blister incidents at some point in 2016, when the ball was showing the characteristics of low seams. There’s now more than one pitcher missing a day for blister-related problems every day of the year. That resonates with what others have found, including Sonne himself and Ben Lindbergh at the Ringer.

But there’s already a problem here: disabled stints for everyone are up 50%. A big leap in blister-related disabled-list stints may just be a result of the 10-day DL, and the fact that teams can be more sensitive to smaller problems with the flexibility those new rules allow. Alternatively, perhaps teams are using blisters to play games with the 10-day DL and keep a larger pitching roster than roster rules technically allow. A look at “specific instances” of blisters shows that, though 2016 and 2017 are robust, they aren’t that out of line with the past, as Sonne showed below. Maybe the 10-day DL is just allowing the same pitchers to jump on the DL more often?

You can get a pitcher to speak theoretically on the record about a possible link. Jeff Samardzija, for example, agreed that there might be some kind of relationship. Maybe. “You might get more blisters if you have to dig deeper into the seams to get the same grip,” he thought, though he isn’t having any problems himself.

Some will even be more specific about the connection. Aaron Sanchez, for example, shared his thoughts with John Lott at The Athletic. Said Sanchez: “Now that we’re starting to see this thing occur with more pitchers around the league, and it’s not just me, if you look at it that way, the ball could be the issue.”

But ask other pitchers about the link, and you start to understand the many variables to consider. In some ways, you’d think higher seams would lead to more blisters because they’d have more friction. “The seams in the minors are higher,” said San Francisco Giants reliever Steven Okert, “and they felt like glass to me. Never had blisters up here, but, then again, I don’t throw a curveball or ride the seams on my pitches.”

The link between curveballs and blisters is one we’ve made here. And we’ve also seen that there are more and more curveballs (specifically) and breaking balls (generally) every year.

League Pitch Type by Year
Season FB% CH% BB%
2007 58.3% 12.0% 28.9%
2008 60.1% 11.3% 27.8%
2009 59.5% 11.1% 28.8%
2010 58.4% 12.0% 28.9%
2011 57.6% 11.5% 30.0%
2012 57.3% 11.3% 30.9%
2013 57.1% 11.7% 30.6%
2014 56.5% 11.9% 30.8%
2015 56.6% 12.2% 30.6%
2016 55.8% 11.6% 31.8%
2017 54.9% 11.7% 32.9%
SOURCE: PitchInfo
FB = four seamers and sinkers
CH = changeups and splitters
BB = sliders, curves, and cutters

Sonne has a Stuff metric that combines velocity and movement for pitches, and has found that league-average breaking-pitch Stuff has more than doubled over the last four years. Perhaps it’s really just those nasty pitches that are leading to more blisters.

Off the record, I received all sorts of confirmation that the balls are a mess, that blisters are a problem, and there’s absolutely a link. That doesn’t help, though, because it’s anecdotal and unsourced. But one off-the-record pitcher said something interesting and direct that provides a link between a possible change in the baseball and the ever-increasing use of breaking pitches.

“Maybe it’s the lower seams, but it’s more likely that it’s the stuff that everyone has to do to get a better grip that’s made the blister problem worse,” that pitcher said.

We’ve seen pine tar, sunscreen, and rosin before. We’ve even seen pitchers get caught for doing what is ostensibly against the rules but is often ignored. When I did a Hardball Times Annual story about mudding the balls, and how inconsistent practices leads to inconsistencies in the balls, I had Mike Thalbulum, the clubhouse attendant for the Athletics, rub up a ball for me.

While he was doing so, he said that the mud did provide grip and defended the practice. “The balls are too slippery without it,” he said. “And if I had some lotion I’d show you what it feels like with lotion. It’s really grippy. Lotion, sunscreen, or some guys obviously use pine tar.” Obviously.

Batters have mostly looked the other way on this issue because they’d rather not be hit by a flying orb, and added grip should theoretically help pitchers corral the ball. But if lower seams — or an emphasis on nastier stuff — is causing more pitchers to go to these grip substances, and those substances are leading to more friction, and that added friction is leading to more blisters, then we’d be losing out on good pitching that we’d all like to see more of as fans. We’d have a problem on our hands.

Then again, that’s a lot of ifs. As convinced as some are of the direct link between lower seams on the new ball and more blisters, it’s not as easy to make that link with research.

With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.

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The Foilsmember
6 years ago

Did a ctrl-F for “Rich Hill” and found no hits so this article is wrong.

(I’m 80% trolling I’m sorry Eno you’re the best)

6 years ago
Reply to  The Foils

I am similarly disappointed.

6 years ago
Reply to  The Foils

Haha. I was actually wondering if Rich Hill was such a big outlier, that it would create a false image of a league wide blister issue in ’16 and ’17.

6 years ago
Reply to  smcdowel26

Seriously if we take Rich Hill out of the equation is there still a big issue? I say yes but maybe that’s because of social media. Because I’ve got to admit before Hills issues I hadn’t heard of blister problems but maybe a few times in the past 10 years.