There’s something dynamic about Cal Raleigh and Jarred Kelenic

If I asked you which Mariner hits the fastball the best, my guess is you’d say Julio Rodríguez. Maybe some consideration would be given to fellow All-Star Ty France, but if we’re defining “best” as “hardest and farthest,” it’s hard to argue with the Mariners’s rookie phenom. However, according to at least one metric—dynamic hard hit rate—the Mariners’ best fastball hitter is not Julio but his fellow rookie (or, at least rookie-adjacent, for our purposes here), Cal Raleigh.

If you’re new to dynamic hard hit rate (DHH%), here’s a brief explainer, courtesy of Connor Kurcon, who developed this stat in a blog post you can (and should!) read here. [If even this is too much stats-ing for you, understandable; skip to the end of this paragraph for the TL;dr explanation.] Basically, hard hit rate (HH%) only measures exactly that—how often a batter hits the ball hard, usually defined as an exit velocity (EV) of over 95 MPH. That’s valuable, because hard-hit balls more often turn into extra-base hits, or at least sharp ground ball base hits that eat up infield defenders. However, HH% alone doesn’t adjust for launch angle (LA), which affects whether a hit turns into an out (there’s a LA “sweet spot”, usually between 15-20 degrees depending on the hitter; too low, and the ball is caught by a defender; too high, and the ball turns into a popout). Kurcon proposes a better measure of hard hit rate would take into account the angle of the ball’s trajectory, to show how not all balls hit at the same exit velocity are equal. Per Kurcon’s research, DHH% correlates well to wOBAcon and xwOBAcon (a statistic that measures how a hitter performs/should perform on contact), which makes it a valuable metric for analyzing a hitter’s performance beyond just hard hit rate. More specifically, Kurcon’s research finds that whereas Tom Tango’s wOBA/xwOBA and wOBAcon/xwOBAcon are descriptive as in they tell us what has happened, DHH% uses similar data to focus on being predictive in terms of telling us what is most likely to happen going forward.

TL;dr: DHH%, dynamic hard hit rate, is a superior measure for predicting future performance compared to hard hit rate because it takes into account launch angle. Compared to xwOBAcon, et al, it has more predictive value.

With that said, let’s take a look at Alex Chamberlain’s invaluable Pitch Leaderboard and see what makes Cal Raleigh so successful against the fastball.

When Mitch Haniger told Cal Raleigh to hunt the fastball, he might not have known he was setting the almost-rookie on a path to a likely All-Star berth, if this kind of hitting keeps up. You probably know that Raleigh is tied with Salvador Pérez for the lead in homers hit by AL catchers, and his current ISO of .253 is highest among all AL catchers with more than 200 PAs, but it’s worth picking apart some of that underlying data. Raleigh does hit the ball hard regularly—in the 72nd percentile, and in the 85th percentile for exit velocity. His barrel rate is in the 91st percentile, and it’s even higher on fastballs—an astonishing 17.2% (part of why Cal’s overall barrel rate of 8.4% has him ranked 30th among all MLB hitters—Julio, with 9.5%, is 15th). So it’s not surprising that Cal grades out with the highest DHH% on four-seamers on the team, at 27.6%. That puts him in line with some of the game’s premier power hitters, like Anthony Rizzo and Rafael Devers, and slightly ahead of Adolis García and Paul Goldschmidt. And while Yordan Álvarez punishes every single fastball thrown his way—a HH% of 75.6%, easily outstripping Judge’s next-best mark of 71.9%—his DHH% is actually lower than Cal’s, at 25.6%.

Part of what explains Raleigh’s high DHH% is his mean launch angle—a sky-high 27 degrees. That’s much higher than the “ideal” average of the mid to high teens, but Raleigh makes it work because he hits the ball so dang hard. According to Tom Tango’s research, which Kurcon builds on in his blog post, a ball hit at 28 degrees over 100 MPH has a correlation to an actual wOBA of 1.261, with a somewhat lower predictive value (.772). Let’s see how this works in action on Cal’s last home run, this moonshot from July 26 against the Rangers:

That ball was hit at a Zunino-esque 34-degree launch angle, but it doesn’t matter so much because it was also hit at an exit velocity of 102 MPH. Because it was hit so high, Statcast hilariously only awards that hit a .480 xBA (expected batting average), but this is another way in which understanding dynamic hard hit rate can give you a more complete picture about how a hitter is having success.

Ideally, Cal will get his average launch angle down somewhat, but as long as he continues hitting the ball very, very hard—and with a max exit velocity that ranks in the 94th percentile in baseball, that shouldn’t be an issue—there should be plenty more Beef Boy Bombs in the future. For Raleigh in particular, it’s a good bet to elevate, as he’s not so fleet-footed as to benefit from a bunch of grounders anyways.

One surprising bit of data from the table: the Mariner with the highest DHH% on any pitch (minimum 25 BBEs, or Batted Ball Events) is Jarred Kelenic on four-seam fastballs. When he makes contact, Jarred hits the fastball harder than any Mariner not named Julio, Cal, or Eugenio. He also hits the fastball in a way that should most often turn into hits, with a DHH% of 38.5%. That’s a higher mark than Juan Soto, Ronald Acuña Jr., Anthony Rizzo or Rafael Devers. However, Kelenic’s average launch angle on fastballs is just a shade lower than Cal’s, at 25 degrees, but he doesn’t hit the ball nearly as hard, with an average exit velocity of just 89.2 MPH. That could mean he’s due for some regression on his DHH%, as seen with his fly ball rate of over 55% while he’s hitting line drives at just a 10% rate this season. Back to hitting line drives, please and thank you Jarred.

Now that we’ve laid the groundwork on DHH%, we’ll take a look at how some other Mariners hitters perform with that metric in future installments of this series, including examining some different pitches. I was surprised by the clubhouse leader on hitting sliders; maybe you will be, too.