Return of the First-Pitch Swing

Not very long ago, I read an article featuring some quotes from Kevin Cash, talking about how he wanted the Rays’ hitters to be more aggressive swinging at the first pitch. At least, I think I read such an article, but I’ll be damned if I can find it. It was probably from Ken Rosenthal, but now I feel a little bad in case I just gave credit to the wrong person. In any case, the article is lost on my internet, but the memory remains, and with it a little research idea. It’s time to look again at first-pitch swings.

With the season basically over, we’re free to examine league trends. You can examine league trends whenever you want, but now there’s no more time for new trends to pop up. Any trends present today are effectively locked in. Last week, I wrote a little bit about the return of offense, and especially home runs, in this season’s second half. If there was a crisis of run-scoring before, concerns have at least been reduced. The run-scoring trend is probably the most interesting one. It’s a big deal if there’s going to be offense again. But there’s another thing we’ve seen happen, even if we individually haven’t noticed. Hidden in the deeper numbers is evidence that hitters are more willing to go up there and swing right away.

The plot below has three lines, going back to 1988, which is as far as the data goes. Because of the magnitudes on the y-axis, year-to-year changes aren’t all that easily visible, but I thought this would be better than a table. Relevant specifics will be discussed after. The three lines: league first-pitch-strike rate, league first-pitch-swing rate, and league first-pitch-called-strike rate.

The general trends are easy to see. Gradually, with one curious spike, first-pitch-strike rate is rising. With it, there’s a rise in first-pitch called strikes. The first-pitch-swing rate takes more of a dip, recovering in recent seasons. Especially in this season.

Relative to last year, first-pitch-swing rate has gone up 1.5 percentage points. That’s the biggest year-to-year jump in the window observed, beating out a previous 0.9-point increase. But, that 0.9-point increase took place in 2001, when first-pitch strikes increased by plenty more. So now look at the blue line. Last year, 33.1% of first pitches were called strikes. This year, the league’s at 31.9%, for a drop of 1.2 percentage points. I know that probably doesn’t seem the least bit exciting, but this is meaningful. That’s the biggest year-to-year drop since 1988, the next-biggest drop being just 0.4 percentage points. That called-strike rate had been rising by an average of about 0.3 points a year. This year, some progress has been reversed.

To simplify everything: Hitters are behaving more aggressively. They had been more and more willing to let pitchers get ahead 0-and-1, but this year hitters have fought back, as if they finally noticed the trend. Pitchers are throwing better stuff than ever. They’re getting more strikeouts than ever. Pitchers these days, when ahead, are incredibly difficult to hit. So hitters have increasingly tried to get to them early, before they get in front. It’s a theory I remember Cash talking about in the article I can’t find. Hitters should go up there ready to hit, because the first pitch might well be the best pitch to hit that they see. Patience for patience’s sake is arguably and probably outdated.

There’s some more, too, pulling from the Baseball-Reference Play Index. They offer a split, based on whether a hitter swung at the first pitch. Now, you’re probably familiar with OPS+. In this plot, you see tOPS+, which compares performance in the split to overall performance. Note that this is not just showing performance on first pitches. It captures all plate appearances, based on whether the first pitch was swung at or taken.

This year, for the first time we know of, hitters who swung at the first pitch haven’t performed worse than hitters who took the first pitch. This clearly isn’t free of certain selection biases, but many of those same biases are present every season. So this year, hitters swung more early, and they’ve been rewarded more for it. Overall, they’ve been put at no disadvantage.

Now for the one big table. Below, all 30 teams in baseball, with their 2014 first-pitch-swing rates, their 2015 first-pitch-swing rates, and the differences between those.

Two-thirds of the teams have increased their rates of swings at the first pitch, with 16 teams increasing at least 1.5 percentage points, and 10 teams increasing at least 3 percentage points. The Braves, by far, have seen the biggest drop, and they’ve been terrible. This year, within the season, the A’s have been more aggressive in the second half than they were in the first. Same with other teams like the Indians, Red Sox, Brewers, Phillies and Rays. The Padres, maybe notably, have seen their second-half rate drop by 5.5 percentage points. I don’t know what that means.

If you’re curious about personnel — Charlie Blackmon stands against the tide. He’s dropped his first-pitch-swing rate from 30% to 8%. Josh Reddick and Jose Abreu are also way down from 2014. But at the other end, Jonathan Schoop is up 17 percentage points. Grady Sizemore and Kole Calhoun, up 15 points. Danny Santana, 14 points; Brian Dozier, 12 points. Matt Carpenter has, this year, opted to become more aggressive — but he’s far from alone.

There’s also some relatively new personnel. There are 69 batters with at least 250 plate appearances, who didn’t have that many plate appearances a season ago. As a group, they’ve swung at 32% of all first pitches, which is north of the league mark. Billy Burns has offered half the time. Yasmany Tomas is close to him. Guys like Kris Bryant and Francisco Lindor have been more aggressive than average. Even Mookie Betts is up, despite ranking near the bottom in first-pitch-swing rate. Betts, as a rookie in limited time, swung at 9% of his first pitches. This year he’s at 16%.

It seems to be a real thing. And if it’s a real thing, we should see it continue into the season to come. For years, batters were OK with the idea of falling behind 0-and-1. They wanted to practice early-count selectivity. It’s always important to be selective, but this year, we’ve seen hitters collectively counter the trend. They’re swinging more at the first pitch they see, and they’re having success. So continues the tug-of-war.