What happens in the first month of a given Major League Baseball season isn't necessarily indicative of what will happen in the next five months, yet the 2021 campaign has already birthed an alarming trend.
Hitting, which was already notoriously difficult to begin with, is now basically impossible.
After more than a month's worth of games, hitters are tracking toward yet another strikeout record by whiffing in 24.3 percent of their plate appearances. They're also maintaining a .233 batting average, the lowest mark in the league's 150-year history.
Based on these numbers, there's never been a worse time to be a hitter in Major League Baseball. And while it might be easy to wave them off as small-sample-size weirdness, they begin to look more like an unavoidable fate as specific causes pile up.
The New Ball Is (Probably) Suppressing Home Runs
For anyone who missed the big news back in February, there's a new ball in play this year.
Contrary to the lively balls that helped facilitate record-setting home run outbursts in recent seasons, the new ball was effectively designed to curb home runs. It's lighter, but also less bouncy and supposedly more prone to drag in the air.
So far, it seems to be working as intended.
Overall, hitters have made gains with their overall fly-ball rate (25.1 percent) and on their average exit velocity on fly balls (92.6 mph). Yet even when compared to past Aprils, there's a conspicuous gap between the expected and actual performance of fly balls this season:
This helps explain why the league is hitting 1.16 home runs per game, compared to recent high-water marks of 1.28 in 2020, 1.39 in 2019 and 1.26 in 2017.
Could this be a fluke? Maybe. Or perhaps a cold-weather thing? Also, maybe.
Yet according to Devan Fink of FanGraphs, hitters are specifically losing home runs on batted balls with lower launch angles. That makes sense because, as he writes, "A baseball with more drag would, in theory, affect these types of events the most."
So if the idea is to hit for power—which it very much is in modern baseball—the standard hitter is in a frustrating spot right now in which the execution is good, but the rewards are artificially elusive.
The New Ball Also Seems to Be Leading to More Strikes
When news of the less lively ball first broke in February, pitchers were surely happy to hear it. And they now seem to be taking full advantage by challenging hitters at will.
So far in 2021, 49.3 percent of all pitches have ended up in the strike zone. That's the highest such mark of the pitch tracking era, which began in 2008.
Unsurprisingly, this is helping to push the league's walk rate down to 8.9 percent. That's by no means a historically low rate, but it's at least down from last year's mark of 9.2 percent.
Pitchers Are Also Nastier
By upping their swing rate relative to 2020, hitters have rightfully determined that the best way to combat pitchers' increased aggressiveness is with increased aggressiveness of their own.
However, many of these swings are going to waste. Hitters are missing on 27.1 percent of their swings, which is yet another high for the pitch tracking era.
Lest anyone launch into a rant about how hitters need to wind the clock back and focus on making contact instead of swinging for the fences, understand that pitchers deserve their share of credit for all the whiffs.
Meanwhile, the league's average spin rate is still trending up:
Because more spin tends to equal more movement, pitchers have an obvious incentive to chase after it. And while it's easy and oh-so-tempting to chalk the rising spin rate up to pitchers ignoring MLB's crackdown on sticky substances, there's another possible explanation for this year's trend.
Take it away, San Diego Padres ace Blake Snell:
The implication here is that the new ball is inherently easier to spin, which hypothetically means that the spin rate will stay up even if Thanos were to come along and snap all sticky substances out of existence.
On Defensive Shifts and Day Games
Even apart from the new ball, hitters still have other disadvantages to contend with in 2021. Defensive shifts, for example.
Teams are using them on the infield less often than they did in 2020, but with greatly improved efficiency. There's a 47-point gap between the actual (.213) and expected (.260) batting average on ground balls against shifted and strategic infields, which is easily the biggest such mark of the seven-year Statcast era.
And if you've been wondering if there's been an unusually high number of day games in 2021, that's because there have been.
Whereas somewhere between 30 and 35 percent of the action (i.e., plate appearances) in a normal season takes place in day games, this year it's 43.3 percent. That may be getting to hitters, whose production hasn't been the same during the day as it has been at night:
This almost certainly isn't a complete list of factors behind the struggles that hitters are having early in the 2021 season, but it'll do as a greatest hits compilation. And in any case, the big question is...
What Comes Next?
In all likelihood, probably more of the same.
Unless MLB is going to reverse course and replace all of the new balls with balls from previous seasons, batted balls are likely to continue underperforming while pitchers keep filling up the zone with high-velocity, high-spin pitches.
As for the defensive shift, it's notable that MLB is already experimenting with regulating shifts at the minor league level in 2021. And frankly, it's a good idea. Nonetheless, regulations on shifts are likely years, not months, away from being a reality at the major league level.
Which is to say that hitters are going to have to keep doing the same thing and hope for better results, or perhaps make some changes so as to avoid all-time offensive infamy.
It would make for a fascinating story if hitters moved en masse through Door No. 2, but don't count on it. Because as rough as this year has been, it hasn't exactly been a 1968-level disaster from either a home run or runs scored perspective. Between that and the reality that warmer weather will help balls carry, hitters have two good reasons to stick to stay the proverbial course.
However, the 2021 season could lead to changes for the long run.
If nothing else, it could further move the needle in favor of policing shifts. It could also convince MLB that more work is needed to bring the ball to an agreeable middle ground. For instance, there might at least be a way to make the current ball less conducive to spin.
Until then, it's about time everyone made peace with the likelihood that the 2021 season is going to be one for the books. Even if it's one that hitters will never, ever want to revisit.
Stats courtesy of Baseball Reference, FanGraphs and Baseball Savant.