How Pitchers are Pitching to Javier Baez

Javier Baez is a player who transcends ordinary prospect-dom. Not just because he possesses extraordinary skills — also because he’s a prospect in whom fans of every team might be interested. Usually, a guy on the farm or a guy just on the roster will captivate locally, but Baez is able to captivate nationally, in a way that few young players are able. He’s not quite on the level of rookie Stephen Strasburg, for whose debut the whole country turned on TV, but people want to know what Baez is going to become. And they want to know how quickly he’s going to become it. His big swings are the hitter equivalent of Strasburg’s big fastballs.

People who are interested in baseball are interested in Javier Baez. They know more about him than they know about the average young prospect. Keeping with the theme, other teams, too, seem to know more about Baez than they know about the average young prospect. Other teams have prepared for Javier Baez, just as we have as fans, and in the early going it turns out Javier Baez has been pitched pretty much exactly as you’d expect that Javier Baez would be pitched.

Let’s watch a sequence, shall we? Baez already played on Monday, and here he is in the first inning, against Carlos Torres. A first-pitch breaking ball:

Ahead in the count, Torres came with some classic high heat:

Now Torres could do whatever he wanted, so why not go back to the well?

It might not have worked, but to this point, Baez saw a low breaking ball and consecutive high fastballs. Torres caught him in between:

Call it a cutter, call it a slider — Baez swung right through it, as he is wont to do to pitches. At this writing, he has two walks and twelve times as many strikeouts. He’s also slugging .517. About that: here’s a pitch and swing from the ninth.

That fastball missed over the middle and found a home in the second deck. Baez to this point has been true to form, with plenty of whiffs and already five dingers. He has his vulnerabilities, but he’s also capable of punishing even minor mistakes, like this slider that just wasn’t low enough:

It’s telling that the catcher called for a low slider in the dirt. It’s telling that Baez destroyed the pitch that was ultimately thrown. It’s telling, how Baez has been approached through his first two weeks in the bigs.

Baez’s extraordinary skill is his bat speed. That’s where the power comes from, and people who observe these things give Baez just about the highest of grades. Because of how quick his bat is, Baez should be able to turn on even blistering heat, but his swing his long and complicated in other ways so there’s a simultaneous belief that he could be vulnerable to fastballs in the right spots. People also question Baez’s discipline, as he might commit too early to pitches that end up unhittable. You’d think that, with a hitter like this, pitchers would be careful, and relatively unwilling to enter the zone unless forced.

Now we’ll do some math. Including Monday’s game, Baez has faced 52% fastballs or cutters. The league average is well north of 60%, so Baez is separated from the mean by a couple standard deviations. He’s surrounded by names like Wilin Rosario, Evan Gattis, and Juan Francisco.

And, including Monday’s game, Baez has faced just under 40% pitches in the PITCHf/x strike zone. The league average is close to 50%, so Baez is separated from the mean by almost three standard deviations. He actually has the lowest zone rate in either league. That includes Josh Hamilton, Pedro Alvarez, and the utterly unprotected Giancarlo Stanton.

Let’s put these together. I’ve calculated fastball-rate z scores and zone-rate z scores. Add them up, and the highest positive numbers will indicate players pitchers aren’t afraid of facing. The lowest negative numbers will indicate players pitchers want to pitch around and/or players pitchers think are willing to chase. Baez’s sample is still quite small, but still, here are the five lowest combined z scores:

1. Josh Hamilton, -5.0
2. Javier Baez, -4.7
3. Pedro Alvarez, -4.3
4. Juan Francisco, -4.1
5. A.J. Pierzynski, -3.6

This quickly, pitchers have adopted an extreme approach against Javier Baez. It’s one of the most extreme approaches in baseball, in terms of avoiding fastballs and avoiding the strike zone. He’s being pitched not unlike Hamilton, Alvarez, and Francisco, which means Baez arrived with a scouting report already written. It isn’t often rookies get treated like this right away.

Of all the rookie seasons we have recorded since 2008, right now Baez is looking at the most extreme careful approach. Juan Francisco shows up again, as he was pitched a little like this, but let’s compare Baez’s first two weeks to the first two weeks of a handful of other elite-level prospects from the last few years:

Player	Fast%	Zone%
Bryce Harper	52%	42%
Giancarlo Stanton	57%	47%
Gregory Polanco	60%	48%
Javier Baez	52%	40%
Mike Trout	69%	51%
Oscar Taveras	69%	45%
Wil Myers	54%	52%
Yasiel Puig	67%	48%

The point of comparison here would be to Bryce Harper. Immediately, Harper was pitched carefully, and he didn’t see a lot in the zone. Harper, obviously, was easy to see coming for years, so he had a reputation before he ever arrived. The same goes for Baez, although he and Harper have been pitched differently as rookies in ways more detailed than this overall glimpse. You might’ve expected Puig to get pitched like this when he first debuted, but instead against him pitchers were particularly fastball-happy. Pitchers have continued to try to find ways to consistently get him out, as Puig’s been able to make rapid adjustments.

Baez hasn’t seen many first-pitch fastballs, relative to the league average. He hasn’t seen many fastballs when ahead in the count, relative to the league average. He’s actually seen more fastballs with the pitcher ahead in the count. While Baez has an overall low rate of fastballs seen, he’s among the league leaders in rate of high fastballs seen, as that’s one of the vulnerabilities pitchers have targeted. You might be able to see that in the following chart of Baez’s pitches against:

Plenty of fastballs up and beyond. Plenty of non-fastballs down and beyond. Non-fastballs are generally supposed to be down, but Baez sees a lot of them, and he has been exposed by high heat. Half his strikeouts have come against fastballs and half his strikeouts have come against breaking balls. He’s willing to chase up, and he’s willing to chase down, and that’s something he’s going to need to work on.

But while he’s exhibited those weaknesses, he’s also exhibited an ability to crush well-intentioned pitches that don’t go where they wanted to. If you throw your high fastball, you can blow it by Baez. If you throw your low breaking ball, you can sneak it by Baez. If you don’t throw your high fastball high enough, though, or if you don’t throw your low breaking ball low enough, Baez is going to swing and he’s more likely to connect, and often when Baez connects, he connects in the way that meteorites connect with the surface of Earth. Pitchers are careful because they have to be careful. They have to be careful because Baez’s skills demand respect.

Javier Baez has been in the major leagues for two weeks. Prior to the beginning of those two weeks, there already existed a Javier Baez opposing scouting report, and we’ve seen pitchers follow along, with varying degrees of success. The second half of that statement could apply to just about anyone, but what’s remarkable isn’t just that Baez arrived with a report — it’s that he arrived with a report so extreme in its recommendations. I suppose Javier Baez can be extreme in a number of ways. I suppose that might be the most appropriate thing.