How Julio Urías Avoids the Long Ball by Justin Choi January 28, 2022 © Tommy Gilligan-USA TODAY Sports A fact: Among the 157 pitchers with a minimum of 400 innings pitched since 2016, Dodgers southpaw Julio Urías has the lowest home run per fly ball rate (HR/FB) at 8.4%. The distance between him and second-place Brad Keller (10.1%) is the same as the distance between Keller and 20th-place Rich Hill (11.8%). It’s no wonder that Urías has been terrific so far in his career – he’s controlled the contact he allows like no other. Also a fact: The reason why xFIP still holds up as a decent ERA estimator is because most pitchers, regardless of their talent level, tend to drift towards a league-average HR/FB rate. Yet here’s Urías, resisting the inevitable pull of regression before our very eyes. Does he have a secret? Or is he merely running from the grim reaper, time ticking with each step? I’m still not sure! But if you’ll allow, here are a few educated guesses that hopefully make sense. First things first, I need to address a common possibility. As Jeff Zimmerman demonstrated years ago, pitchers with higher fly ball rates also have lower HR/FB rates. That’s because they also get their fair share of popups, so the denominator ends up outpacing the numerator. But even though Urías isn’t a groundball pitcher, he isn’t a notable fly ball pitcher, either. He’s 37th among the aforementioned 157 in terms of fly ball rate – above-average, sure, but not extreme enough to explain his deflated career HR/FB mark. Our answers, if any, lie elsewhere. Instead, let’s dig into Urías’ repertoire. How do you induce a bunch of harmless fly balls? One method is to rely on a fastball with plus ride – hitters have a tendency to swing under one, which works to a pitcher’s benefit. Take John Means as an example, who in 2021 led all starters in popups per batted ball. But while Urías’ heater generates a solid amount of movement, it’s nothing to write home about. Of the 357 pitchers who threw at least 250 four-seamers last season, Means ranks 37th in terms of unadjusted vertical break. Urías, meanwhile, ranks 105th, tied with Cristian Javier and Tony Gonsolin. That’s not a slight on any of those pitchers, but again, on this score Urías appears good rather than great. But fear not, because the Dodgers lefty does have one distinct trick up his sleeve. When assessing the spin imparted on a pitch, we can break it down into two types: transverse and gyro. The former is what contributes to a pitch’s movement, while the latter lays dormant, which can be either beneficial or detrimental. Some sliders induce a ton of confused swings due to how little they move. Conversely, an inactive fastball wouldn’t work as well. It’s why pitchers dedicate time to adjusting their arm angles or grips, in search of an axis that will grant them a perfect blend of spin. What makes Urías unique, though, is that he averages a healthy amount of ride despite just 81% of his total spin being classified as transverse, or “active.” He isn’t a total outlier in this sense, but we can see that he does stand out among a horde of pitchers, represented as points on the scatterplot below: Urías is the point in red, occupying the exclusive “less drop and lower active spin” quadrant. And there’s a subtle benefit to getting more mileage there than others: It’s been theorized that gyro spin is what causes a pitch to gain late break as it approaches home plate, and for fastballs, that translates to extra zip or cut that catches hitters off-guard. Not a ton, mind you, but the difference between a barreled ball and a mishit one is often mere inches. That small margin might be doing Urías favors, and it’s what separates him from the prototypical starting pitcher. Of course, a slightly eccentric fastball isn’t all Urías has to offer. Starting in 2020, he began morphing his curveball and slider into a singular pitch, a process he perfected the following year. Rather than two breaking balls, Urías now throws what is known as a “sweeper”: a slider that doesn’t have much depth but instead creates monstrous horizontal break, darting away from same-handed batters. Sweepers have become a hot commodity as of late – batters can’t help but whiff at them, and select teams have hopped on the bandwagon. But there’s another, more obscure component to the sweeper that makes it valuable. In 2021, batters put a total of 32,092 breaking balls into play. By applying the parameters set forth by Dan Aucoin, we can classify 5,721 of them as sweepers; the rest failed to meet one or more requirements. Now, time for the fun part. Here’s a graph showing the launch distribution of those sweepers: You’ll see that the distribution is skewed to the left, meaning a significant chunk of the batted balls were of higher launch angles. Maybe this doesn’t really resonate with you, and that’s fine – I think it’s more cool than informative, too. So how about this? Beyond a certain launch angle, balls become automatic outs no matter how hard hitters attack them. Let’s designate 40 degrees as the tipping point, because last season, hitters mustered a .048 wOBA on balls struck at that angle or above. With this in mind, here’s an extremely simple table: Sweepers vs. Non-sweepers, 2021 Category 40+ LA% xwOBAcon Sweepers 22.7% .339 Non-sweepers 14.8% .360 SOURCE: Baseball Savant Why throw a sweeper? Because they’re conducive to popups! I’m not exactly sure why this is the case; perhaps the cross between extreme horizontal movement and minimal vertical movement is the driving factor. In any case, it worked for Urías. His wicked slurve limited hitters to a .181 wOBA, with plate appearances often ending like this: Lest we forget, Urías also throws a changeup. It also does a superb job of suppressing hard contact, but unlike his sweeper, it does so through an abundance of grounders. That keeps Urías’ fly ball rate from spiraling out of control, besides acting as a handy tool against right-handed hitters. When hitters do manage to elevate the changeup, though, they traditionally haven’t had much luck. In fact, Urías is one of two pitchers last season – José Suarez is the other – to not allow a single home run on a changeup thrown at least 400 times. There’s nothing special movement-wise, but it’s effective by virtue of providing contrast within Urías’ pitch mix. Also, while this part is a bit speculative, I wanted to point out a quirk within Urías’ delivery. One of baseball’s final frontiers is the quantification of deception. Ben Lindbergh wrote an extensive primer on the subject last September that revolved around Yusmeiro Petit, the A’s soft-tossing reliever. In Lindbergh’s article, hitters are quoted as describing Petit’s ability to hide the baseball, which turned a seemingly middling pitch into a nightmare. Urías isn’t on Petit’s level, but he’s a disciple nonetheless: Check out the short arm action – it keeps the ball tucked to Urías’ lower body, and that’s about as much as he lets the hitter see. It’s common for pitchers’ shoulders to open in accordance with the hips, but Urías keeps them relatively closed off. That maneuver conceals the ball once again: By the time the hitter can get a clear look, it’s already too late. Urías is ready to fire off whatever pitch was called for: Taking away a hitter’s look at the ball also means taking away the subtle cues one can use to determine the shape or path of an incoming pitch. It also means hitters are less likely to find the right timing to achieve ideal contact, and maybe that’s where Urías gains an advantage. From the moment his hand leaves the glove up until his point of release, the ball is seldom to be found. The streamlined delivery is unlike that of Andrew Heaney, who – you guessed it – has one of the league’s highest rate of home runs per fly ball. But that’s an article for another day. Despite everything, there definitely is some amount of good fortune baked into his HR/FB rate. If we raise the minimum number of innings pitched to 500, Noah Syndergaard emerges on top with a rate of 10.1%. If we raise it to 600, the crown now belongs to Zack Wheeler and his 11.0% mark. It’s nearly impossible for a pitcher to allow as few home runs off his fly balls as Urías does, and chances are that his next few seasons will see an uptick in hard contact. That won’t necessarily be because Urías has gotten worse; a correction upwards just seems inevitable. His sporadic workload prior to 2021 might have also contributed to an abnormal HR/FB rate, and he’s now slated as a fixture of the Dodgers rotation. But overall, I’m sold on the idea that he can sustain a lower home run rate than most throughout his career. The four-seamer gets enough transverse spin to thrive at the letters, and it also packs enough gyro spin to shift the pitch’s axis. The sweeper is verifiably great for inducing popups galore. The changeup is there, too, mainly to keep the ball on the ground but also to mute it when it ends up in the air. And tying it all together is a deceptive arm action that keeps opposing hitters guessing. To paraphrase Foolish Baseball, allowing home runs is for suckers. And Julio Urías is no sucker.