The Two Major Takeaways From This Year’s Spring Training

Spring training is far too long. I think just about everyone agrees on that. But spring training is also wonderful, and it’s wonderful for two reasons. One, there’s baseball to watch. Baseball free of stakes and emotion, sure, but baseball, precious live baseball. And two, new baseball means new baseball statistics. They’re statistics we hardly make anything of, and they’re statistics that can be hard to track down in the first place, but numbers are numbers, and after an offseason spent reflecting on the same data over and over, it’s good to have new figures to consider. New numbers help fill the void in between new games.

You know that, on the individual level, spring-training stats are nearly worthless. The signal is drowned out by the noise, for so very many reasons. And even on the team level, you don’t want to take anything too seriously. Yes, four of the five best spring-training records in the American League belong to the Red Sox, Astros, Indians, and Yankees. But over in the National League, the Marlins have a better record than the Nationals. The Padres have a better record than the Cubs. Why should we care about team-level results? Even the teams barely care about team-level results.

And yet, there are league-level results. League-level results, covering hundreds of games and tens of thousands of plate appearances. Only there, when you put everything together, can you find numbers that might have real meaning. To get to the point more quickly, I’m just updating something I wrote about three weeks ago. Spring training is just about complete, with opening day right around the corner, and the league-level numbers are striking, in two areas in particular.

I always planned to update that post, because, while I liked the information just fine back then, I arguably jumped the gun. At that point, spring training was only around 40% complete. The spring training that had been played was the earliest spring training, with the least big-league-y rosters. Now it’s almost all in the books. Now we can observe what spring training has said, for real.

Compared to last year’s spring training, batting average hasn’t budged. On-base percentage hasn’t budged. Walks are just barely up, while strikeouts are up 7%. Bunts are down, and hit batters are up. Hit batters, in fact, are up 15% from a year ago, with the highest spring-training rate since 2006. That’s somewhat interesting — maybe pitchers are increasingly willing to work inside. Maybe something else. We’ll monitor hit batters over the course of the season, but we should move on to the two biggest takeaways. First up, there’s the matter of the home run. I’ve decided to calculate the rate of home runs on contact. In the following plot, you see spring-training rates going back to 2006, and the same for regular-season rates.

When I looked at this a few weeks ago, the rate was clearly up. Since then, it’s only increased further. Last spring, the rate of home runs on contact was 4.0%, which was the highest rate in the window. The rate for this spring is sitting at 4.6%, which works out to an increase of 14% year over year. Think about that for a moment. I know the rates look tiny by themselves. Home runs, as far as batted balls are concerned, remain uncommon. But this isn’t a small change. A change of 14% is enormous. As you can see in the plot, the spring rates and the season rates kind of mirror one another, with the season rate typically being higher. Therefore, we could be looking at a continuation of the home-run surge. And we could see a sizeable bump.

I haven’t analyzed the weather in Arizona and Florida, to see if conditions have been atypically home-run friendly. I’m skeptical. It’s possible this spring is just reflecting last season’s power spike, which wasn’t so apparent in March. There’s nothing we can know for absolute sure. It’s just, there’s compelling reason to believe the home runs are going to go up again. It was harder to get an answer to this than I expected, but spring-training baseballs are new, as opposed to being holdovers from the previous year. Presumably, new spring-training baseballs are manufactured in the same place as new regular-season baseballs. There’s zero evidence the ball has been de-juiced. The ball they’ve used in spring has been flying, and you could say the home-run era is still trying to find its level. Things have yet to stabilize.

Related to the above, we have fly balls. As I’ve mentioned before, spring-training batted-ball data is annoying, because there aren’t just normal ground-ball rates. Instead, what’s available at MLB.com are ground-ball outs and air-ball outs. That’s not ideal, but we can also assume the out rates on grounders and flies have remained fairly similar. Spring-training BABIP hasn’t really moved; it’s always around .315. So there can be real meaning here, and, as such, take a look at the ratio of ground-ball outs to air-ball outs.

Again, you see the rates mirroring one another. And this spring, the league-wide ratio has taken a dive. Back in 2015, spring training hit a peak ratio of 1.28. The next year, it was 1.27, and the year after that, it was 1.23. This spring, we’re looking at 1.14. There’s a chance there’s been some kind of change in how batted balls are recorded. That’s happened before in the past, when scorers are given new rules to score by. I think the likelihood, however, is that it’s not scoring that’s changed. This spring, for every grounder, it seems like there have been more flies and liners.

Just as with homers, this isn’t anything you wouldn’t expect. This is even a partial explanation for the home-run rise, since homers all come from balls hit in the air. Grounders don’t do anything good for a home-run rate. But ever since we’ve been talking about the home-run spike in the middle of 2015, we’ve been looking for evidence of a league-wide shift to the air. There’s been no shortage of anecdotal evidence, but the league-level changes have been very small. What we could have a hint of here is a change that isn’t so small. What’s suggested by the plot is that more and more hitters are trying to generate loft, and pitchers haven’t been so able to counteract it. In some sense this has felt inevitable, but the change might be picking up speed and momentum. Extra-base hits are found in the air. Extra-base hits are better than singles. Singles are less valuable anyhow in an era with so many strikeouts. You don’t need to hear more about why fly balls are productive. Spring data suggests the league has been listening.

The regular season ahead will reveal the actual truth. Spring training is basically a trailer. It looks like we’re in for a similar movie, but with even more bombs and explosions. I don’t know if anyone knows how many explosions are too many explosions, but baseball appears determined to find out.