The NL West is a two-team division these days, but that wasn’t always so certain. In 2019, the Diamondbacks burst onto the scene as a potential playoff team — not the equal of the Dodgers, but a thorn in their side nonetheless. The Snakes didn’t boast the same top end as their Hollywood rivals, unless you had a wildly optimistic opinion of Ketel Marte, but they did have depth, personified by Carson Kelly, the highlight of their return for trading Paul Goldschmidt.

That 2019 season showed Kelly’s promise. In 365 plate appearances of platoon work, he compiled 1.8 WAR, combining competent work behind the plate with a 107 wRC+. That batting line was buoyed by a 13.2% walk rate and a juicy .232 ISO, neither of which seemed particularly convincing, but his central skills — good plate discipline, the ability to draw a walk, enough power to be respectable — all pointed to continued offensive competence.

The 2020 season wasn’t so kind. A .221/.265/.385 line was good for a 70 wRC+, and those flashes of light from the previous year — his walk rate and power on contact — both dipped. It was only 129 plate appearances, and it came with a .250 BABIP, so it was hardly a season he couldn’t recover from, but his swoon mirrored Arizona’s: 25–35, last in the NL West. After the Padres went nuclear this offseason and with the Giants continuing to hit on interesting players, it was easy to move on from the Diamondbacks and their bushelful of interesting but flawed players, Kelly included.

Secretly, though, Kelly’s 2020 was actually encouraging. Not the top-line numbers, mind you; those were terrible, like we talked about above. But consider: Kelly’s ISO (extra bases per at bat, if you’re unused to seeing that; it’s a measure of power) dropped from .232 to .164, and he totally deserved that. His barrel rate halved, his hard-hit rate declined precipitously, and he traded line drives and fly balls for grounders. Bad power central!
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I had a hard time writing the introduction for this article. Actually, strike that — I had one in mind the whole time, but I kept trying to come up with alternatives. Here’s the deal, though. I’m obsessed with Corbin Burnes (in a wholesome, “I love watching this guy pitch” kind of way), and I’ll use any excuse possible to write about him. His seeming transformation into a pitching demigod? Yeah, that certainly qualifies.

If you’re looking for the origins of both my Burnes obsession and his journey from prospect to ace, look no further than his first start of 2019. Burnes threw a gem, from a strikeout perspective at least, notching 12 K’s against a single walk. He also gave up three home runs and lasted only five innings — seems bad! The culprit was a fastball that spun ineffectively, some unholy blend of four-seamer and cutter that hitters had no trouble timing and obliterating.

Think “obliterating” is an extreme word choice? Burnes had an 8.82 ERA in 2019 and a 6.09 FIP. He gave up 17 homers in 49 innings, leading to a two-month trip to the minors. Batters barreled up 13.7% of the fastballs they put in play, which produced 10 of those homers. They whiffed on less than 20% of them, a poor result for such a hard, high-spin pitch. And he simply didn’t get the ride that four-seamers need, a prerequisite for missing bats. Read the rest of this entry »

The strike zone doesn’t exist. Not physically, at least; it’s a rough boundary that varies based on how each umpire looks at it and how each batter stands. Catchers influence the shape, too; smooth hands can turn balls to called strikes, while cross-ups tend to do the opposite.

This year, the zone seems particularly amorphous — maybe it’s just my imagination, but I feel like I can’t turn on a broadcast without hearing about an inconsistent zone. Of course, hearing isn’t believing, and there are botched calls every year. Just because there have been some memorable ones this year doesn’t necessarily mean the overall rate of missed calls has changed. Let’s find out if it has, or if it’s merely imaginations running wild with the backdrop of fan noise.

For a rough idea of ball/strike accuracy, I went to Statcast data. For every pitch, Statcast records a top and bottom of the strike zone, as well as where the pitch crossed the plate. Armed with that data as well as some constants like the size of a baseball and the width of home plate, I measured how far out of (or into) the strike zone each pitch of the 2021 season was when it crossed the plate.

This data isn’t perfect. The top and bottom of the strike zone are approximated, and the plate isn’t a two-dimensional object, despite the fact that our data on it is represented that way. We aren’t considering framing. But we have previous years of the same data, which is great news. We can use the previous years to form a baseline, then see if this year’s data represents a meaningful change. And because we have a huge chunk of data, we can at least hope that framing comes out in the wash. Read the rest of this entry »

Julio Urías is only 24, but it feels like he’s been in the big leagues for a decade. Called to the majors at only 19 in the 2016 season, he’s been a part of the Dodgers’ future and present for a half-decade. When you start that young, much of your development happens at the major league level. In Urías’ case, that means all kinds of changes. Today, though, I want to focus on one: a curveball that has shape-shifted over time before arriving at a tremendously interesting final form.

When Urías came up, he threw a curve with two-plane break, something between a curve and a slurve. As you can see on our handy Pitch Type Splits, it featured 7.4 inches of horizontal break and only 2.9 inches of drop. In his next three seasons, all injury-affected, he turned the pitch into more of a classic curve — more drop than horizontal movement. 2020 saw a return to his original curveball shape. 2021? Well, it’s weird:

Is it a return to his old form? Is it an acceleration of his old form? Is it something else entirely? Let’s delve too deeply into some gifs and math and find out. Read the rest of this entry »

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On his 110th pitch of the night, Carlos Rodón hit 99 mph on the radar gun. It was a wasted pitch, a ball that evened the count to Jordan Luplow at 2-2. Four pitches later, Rodón slowed it down, dropping in a changeup that Luplow rolled harmlessly to third base. Yoán Moncada fielded it cleanly and fired to first for the last out of the game. Rodón had thrown a no-hitter, the first of his career.

Don’t worry, we’ll get to that momentous event. I want to talk about that fastball first, though, because it’s also remarkable. That pitch was the fastest pitch a White Sox starter has thrown this year — tied, actually, with a Dylan Cease offering. Cease is a flame-throwing 25-year-old with a 70 fastball grade — a plus-plus pitch that anchors his entire game. Rodón hadn’t crested 93 mph in average fastball velocity since 2017. He pitched only 7.2 innings last year, and hasn’t topped 150 since 2016. In an increasingly young man’s game, Rodón seemed somehow past his prime at only 28.

In last year’s playoffs, he made the roster as an afterthought. He faced three batters, as a last resort in the team’s disastrous playoff exit — all three reached, the third on an intentional pass that fulfilled the three-batter minimum, and it would hardly have been a surprise if that was his last pitch in black and white. In a money-saving move, the Sox didn’t tender him a contract after the season.

He signed a one-year deal in February to return to the team, but his rotation spot was anything but guaranteed; the team held a more-or-less open competition for its fourth and fifth starter spots this spring. An offseason workout regimen and some rare but welcome good health helped him secure a spot, and a successful first start against the Mariners — 95 pitches and nine strikeouts in five scoreless innings — cemented it.

That brings us back to Wednesday night. After an uneventful top of the first, the White Sox offense did their best to remove all drama from the game. They pounced on an ineffective Zach Plesac, chasing him from the game after seven hits and six runs. Rodón, whose first fastball of the night left his hand at 91.1 mph, sat in the dugout and watched. Read the rest of this entry »

Last week, Justin Choi published an examination of the new ball. The results were — well, you should read it for yourself, but they were muddled, to say the least. Home runs are down! Exit velocity is up! Liners got better, fly balls got worse. It’s enough to make you wonder whether we’ll ever know the answer. It’s also catnip to analysts, and so today I’d like to present some supplemental evidence that only makes me more confused.

There were two key conflicting findings in Justin’s research. First: home runs are down, and fly balls aren’t carrying as far, on average, as they did last year. Second, overall exit velocity is up league-wide, whether you care about broad averages or the hardest-struck balls. The two effects — harder hits, less carry — benefit line drives over fly balls, because line drives both spend less time in the air and depend less on distance for their value.

I wasn’t really sure what to make of the fact that fly balls are carrying less. There are so many confounding factors — weather, new humidors, angle, stadiums, the list goes on and on — that I don’t think I’ll ever be able to disambiguate them all, but I took a crack at it. Read the rest of this entry »

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Did you know that Tyler Glasnow was once a Pirate? Yes, like every other baseball writer in existence, I’m contractually obligated to point that out in any article I write about him. Good news, though — I promise that’s the last time I’ll mention them in this article, because I want to talk about something that Glasnow has done this year to add a much-needed wrinkle to his game.

The Glasnow of the past few years was a two-trick pony, if such a thing exists. Trick one: a fastball that sits around 97 mph and touches 101 when he needs it. It doesn’t stand out for exceptional rise or transverse spin efficiency, but it doesn’t need to. Glasnow’s velocity and extension make for a flat-planed, dynamic pitch that both misses bats and induces weak contact.

You already knew that, because you can’t watch a Glasnow appearance without marveling at the graceful explosion of the pitch, seemingly catapulted by his smooth delivery. Here, watch him overpower J.D. Martinez:

Ah, what a joy to watch. Read the rest of this entry »

Dylan Bundy’s career has hardly flown under the radar. He was arguably the top pitching prospect in baseball when he debuted, and his subsequent injury troubles made the next part of his career a well-known cautionary tale. When he returned to effectiveness in the second half of 2019, then broke out in 2020, it was a story arc we’ve all seen before: the post-hype prospect makes good.

While you might know that, you probably don’t know the secret skill that’s powering Bundy’s resurgence. It’s not a high-octane fastball — he’s lost that since his prospect days. It’s not a gaudy swinging strike total — he’s no slouch in that department, but nor does he excel. What Bundy does best is loop breaking balls through the strike zone and coax batters into taking them. He might be baseball’s best at it, and the piles of free strikes he racks up power the rest of his game.

Want a quick visual before we dig into the numbers? Tim Anderson is a free swinger, but even on 0-1, he couldn’t unlock his bat against this slider:

Want it with a curveball? Watch Bundy demonstrate the low and away boundary of the strike zone to Adam Eaton:

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