Jose De Leon Looked Exactly as Advertised

Jose De Leon made his debut over the weekend and he allowed four runs in six innings to a mediocre Padres lineup. Though he came away with the win, it would be easy to scan the box score and conclude that he probably didn’t deserve it. Just another amped-up rookie going through some major-league jitters. It’s not an uncommon course of events. The first time for everyone ought to be a freebie.

The Dodgers, though, would tell you that De Leon pitched better than that. And even the box score itself would tell you that De Leon pitched better than that. Along with the four runs, De Leon whiffed nine without issuing a walk. Of course, yeah, it was just the Padres. And you don’t ever want to allow four runs. No one’s quite sure when De Leon is going to start again. But the reality of his debut is that he looked exactly as advertised. There are reasons why De Leon has never been traded.

I want to show you a plot and a table. They kind of say the same thing, but then, I’ve always been told that if you want people to remember something, repeat it. As for why De Leon has been advertised so highly in the first place — with each season, he’s gotten better. And in this plot, you’ll see Triple-A pitcher statistics. I’ve included contact rate, and the rate of pitches thrown while ahead in the count. De Leon is highlighted in blue.


There, De Leon occupies the proper quadrant. That shows that he’s been both hard to hit, and frequently in control. A pitcher who gets ahead and misses bats is likely to be a good one, and now, to basically repeat myself, here are Triple-A pitcher strikeout-minus-walk rates, given a minimum of 10 starts:

Top Triple-A Starters
Pitcher K-BB%
Jose De Leon 26.6%
Jameson Taillon 23.3%
Blake Snell 23.0%
Phil Klein 22.7%
Chad Green 21.6%
Joe Musgrove 21.1%
Jharel Cotton 21.1%
Alex Reyes 21.0%
Jose Berrios 20.6%
Adalberto Mejia 19.3%

Right. This is why Dodgers fans were waiting for De Leon impatiently. A year ago, he succeeded in Double-A, and this year, in Triple-A, he caught fire. You’ll notice he’s the leader in that table. It’s a table with some awfully intriguing names in it. And over De Leon’s last five Triple-A starts, he recorded two walks and 45 strikeouts. It seems like he conquered the level. That made him fit for a big-league promotion.

And now we can say that, over De Leon’s last six starts, he’s recorded two walks and 54 strikeouts. One of those starts came in Dodger Stadium. Let’s quickly review the ways in which De Leon looked like he should’ve been expected to look.

So many strikes

De Leon was one of the league-leading control artists in Triple-A. You probably gathered that from the information above. He threw almost 69% of his pitches for strikes, and he threw 41% of his pitches while ahead in the count. Against the Padres, De Leon threw more than 67% of his pitches for strikes, and he threw 43% of his pitches while ahead in the count. Maybe you don’t have a good idea of the league averages! Those would be 64% and 36%, respectively. With these numbers, individual percentage points can mean a lot. One percentage point refers to one pitch a game, basically. De Leon frequently found himself ahead. The Padres weren’t able to scare him wild.

Deceptively live fastball

De Leon doesn’t really work with plus velocity. He throws his fastball in the low 90s, sometimes dipping as low as 89, and sometimes reaching as high as 95 or 96. So he’s not a fireballer, and he doesn’t have the benefit of tremendous extension. Yet if the fastball were mediocre, the numbers would be mediocre. There’s something about the pitch that seems to give hitters fits, and the Padres swung through De Leon’s fastball 11 times. Here’s one:

It helps that De Leon’s fastball looks so much like his

Excellent changeup

De Leon’s best weapon is his changeup, which is relatively uncommon for an upper-tier pitching prospect. The Padres swung through six changeups, and De Leon was willing to throw the pitch in any count in any situation, as far as I could tell. A pleasing whiff:

There’s a large difference in velocity between De Leon’s fastball and changeup, and there’s also a large difference in vertical movement. However, there’s a rather small difference in horizontal movement, which, anecdotally, seems to be best. That way, the fastball can disguise the changeup, and the changeup can disguise the fastball. The arm actions are implied to be similar, and the same goes for the spin. De Leon isn’t a two-pitch pitcher, but the two pitches do work very well together. That should help him to avoid any horrible platoon split.

Occasional breaking ball

De Leon didn’t throw many breakers against San Diego. In part this could be because he barely faced any righties. But, also, the breaking ball is his worst pitch. Which isn’t to say it’s bad.

It’s just not up there with the other stuff. Various scouting reports claim the breaking ball is in the vicinity of average. If there’s one area where De Leon could really stand to improve, it’s here. Without a great breaking ball, he’s a quality prospect. With a great breaking ball, he’d be a nightmare.

Batted balls in the air

Throughout the minors, De Leon has been a fly-ball pitcher. I don’t see any reason to believe that’s going to change in the majors, and against the Padres, De Leon yielded a high average launch angle. The downside is that some fly balls can be hurtful. The upside is that others can be basically the same thing as strikeouts.

De Leon generated a high pop-up rate in the PCL, and he carried that over into his debut. He gets hitters to swing under the baseball, giving him both whiffs and virtual whiffs. Looking only at strikeouts, De Leon has been fantastic. Fold in the other kind of automatic out and he appears even better.

A dinger

If there’s a vulnerability, it’s this:

Consider it a consequence of having two and a half pitches. Consider it, also, a consequence of being a fly-ball pitcher in the first place. The advantage of getting groundballs is that grounders aren’t homers. The disadvantage is that grounders lead to hits and errors. The advantage of getting fly balls is that flies are often easy outs. The disadvantage is that some flies are dingers. De Leon hasn’t had a horrible homer problem, but they will happen. He throws strikes and he doesn’t have an advanced breaking ball to offer a consistent third look. The Padres got their homer. At least, for De Leon, because he throws so many strikes, most of the homers should be solo shots.

In another organization, Jose De Leon would be a rotation regular. With the Dodgers, even though they’ve had to deal with an impossible number of injuries, the rotation picture is still oddly crowded, so it’s unclear when De Leon will get another go. This much is certain: Future opportunities are coming. The Dodgers like what they have, and, they ought to. They know that De Leon is ready to be a big-league starter. And now, so do you, for many of the reasons De Leon showed in his first six innings. He’s not perfect, and he’s not as good as he could be, but prospects don’t get much more advanced.

Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.

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6 years ago

I so want that graph to be interactive, I badly want to know who the dot just to the right of JDL is, and the guy way down at the bottom (I want to guess that one is Glasnow? But was he pitching ahead that often?).