If you wanted to design a puzzle to attract my interest, you couldn’t do much better than pitchers who throw both sinkers and four-seamers. I love thinking about pitching. I love thinking about fastball spin, and I’ve been having a blast looking at approach angle recently. Want to kick it into overdrive, though? Add in platoon splits, and we’re really cooking with gas.

One of those weird, of-course-this-exists-but-we-don’t-talk-about-it splits is groundball pitchers against flyball hitters and vice versa. I first learned about this split in The Book, and while it’s always made sense, Alex Chamberlain put it into a pretty picture recently that brought it back to mind for me:

fly ball hitters perform better against ground ball pitchers, and ground ball hitters perform better against fly ball pitchers

(y-axis: pitcher influence on launch angle
x-axis: hitter LA, absent pitcher influence
colors: hitter wOBAcon bins) pic.twitter.com/K43Kj868T5

— Alex "Oxlade" Chamberlain (@DolphHauldhagen) January 21, 2022

There are some terms you might not know on there, like pitcher influence on launch angle. For that, you should read Alex’s work on launch angle here. Honestly, you should probably just read all of Alex’s stuff anyway – but particularly for this, his work is invaluable.

The key takeaway here? Against groundball hitters, sinkers are an excellent choice of pitch. The hitter tends to hit the ball into the ground and sinkers generally influence launch angles downward. The result is frequently a grounder, which is great for the defense. Similarly, if you’re facing a fly ball hitter, you want them to hit it even higher into the air, which means a four-seamer with solid rise is the ticket. Read the rest of this entry »

Is throwing a four-seam fastball down the middle a good idea? Regardless of whom you ask, the answer is probably no, and for good reason – the heart of the zone is where the majority of hard contact occurs, and fastballs are the most contact-prone of any pitch type. This disdain is rooted in our baseball lexicon, too. You’ll notice that after a ball is hit out of the park, broadcasters tend to remark that the pitcher “left one over the middle” or “hung his fastball.” The location is often to blame.

That doesn’t stop pitchers from trying, though. That’s not always because they want to – command comes and goes, after all – but it’s also because hitting a baseball is extremely difficult. Swings and misses happen! Bad contact happens! In each season since 2015, when Statcast data became public, hitters have accumulated a negative run value against down-the-middle fastballs. They’re still in the red despite seeing easier pitches. Though no pitcher would want to live solely in the middle, it makes sense why one might venture there.

But 2021 brought changes to the majors, and this is one of them: Hitters did worse against so-called meatballs than ever before. Here’s a graph that shows the league’s run value per 100 against fastballs in Baseball Savant’s “Heart” zone. Again, 2015 is the starting point:

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“Just platoon it.” Whenever a team has a weak spot in their lineup, that’s the first thing I think of. Limp left field production? Just sprinkle some platoon on it, and you could be living large. Second base got you down? You’re just one platoon away from competence, or even excellence if you play your cards right. Second base and left field are bad? Bam, platoon them both!

It isn’t actually that easy. If you want to deploy a platoon in the majors (as opposed to in theory, my favorite place to deploy platoons), you have to wrangle with reality, which is notoriously unforgiving. In that vein, this is an article I’m writing to remind myself how hard it is to run multiple platoons at once. It’s not necessarily a reason not to platoon. It’s not even a critique of platooning. It’s just that in my head, and potentially in yours, teams are passing up platoon spots left and right. Here are some reasons why that isn’t true.
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On the surface, popups may seem a bit mundane. Typically, the ball isn’t even visible on the broadcast and they are nearly always converted into outs. Nearly always isn’t always, though, and dropped popups are a treat to behold. And even if you aren’t lucky enough to see one actually drop, plenty of weird things can happen on plays that start off routine:

Since it’s the middle of the offseason, I thought it would be a good time to take a closer look at the popups of 2021. I don’t want just any old popups, though. I want the best of the best — the popups that cause players to lose their feet, the ones that make the crowd “ooh” and “aww” as the ball simply refuses to come down.

The easiest way to find these sky-scraping popups is to base our search off of exit velocity, as balls hit harder will go higher. An exit velocity of at least 97 mph seemed like a good cutoff point. Any lower, and the popups would start to feel less impressive; any higher, and the sample wouldn’t be large enough to satiate my desire to watch this sort of play. That cutoff left me with 126 popups representing the hardest 1.5% of popups hit this season (if you’d like to follow along, you can find the whole batch here on Baseball Savant). Read the rest of this entry »

Back in December, I wrote about Cedric Mullins’ breakout 2021 season, the catalyst for which was a decision to stop switch-hitting and begin batting exclusively from the left side of the plate. By dropping his right-handed swing, Mullins, a natural lefty, could focus on honing one swing instead of struggling to maintain two separate swings.

Switch-hitting has always been a rare skill throughout baseball history, but the number of batters who can swing both ways has dwindled in recent years. From that previous piece:

In 2021, just 17 qualified batters (13.1%) were switch-hitters, right in line with the league-wide average over the last decade. Compare that to the decade between 1986 and ’95 (excluding the strike-shortened 1994 season), when more than one in five qualified batters (21.1%) hit from both sides, with a peak of 24.8% in ’89. With modern baseball strategy so heavily emphasizing the platoon advantage, it’s surprising to see so few switch-hitters these days. Giving up that advantage in every at-bat is a radical decision, and there’s barely any precedent for it.

The number of players who have dropped switch-hitting after making their major league debuts is tiny. J.T. Snow did it in 1999, halfway through his career. So did Orlando Merced in 1996. Shane Victorino flip-flopped between switch-hitting and batting right-handed after injuries forced him to give up left-handed batting at various points during his career. More recently, Tucker Barnhart gave up switch-hitting in 2019.

After seeing the success Mullins had after giving up swinging from the right side, the obvious follow-up question is whether we can identify any other switch-hitters who might benefit from focusing on swinging from one side or the other.

The extremely small number of players who have actually made the decision to stop switch-hitting at the major league level should tell us that this isn’t a silver bullet solution to a player with a wide platoon split. Anecdotally, more players stop switch-hitting in the minors because they have a lot more to gain if the adjustment pays off. For those players who have already made it to the majors but haven’t truly established themselves, like Mullins, it’s a risky decision. They’d be making the change against the best the sport has to offer, likely resulting in a significant adjustment period. Still, with teams focused on finding every miniscule advantage to wring out of their rosters, it’s a worthwhile question to pursue.
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Writing about baseball isn’t the most predictable task. I often don’t know what my topic will be until the dust settles, hours after rummaging through a pile of numbers that, at first glance, makes little sense. For example, this article started off as an inquiry into Darin Ruf. Of all the journeymen to stop by the KBO, experience a resurgence, and return stateside, he’s by far enjoying the greatest success – who would have guessed?

As a right-handed hitter, Ruf’s primary asset is a knack for mashing lefty pitchers. He can hold his own against righty pitchers, too, posting a 126 wRC+ against them last season. But detractors might point to a .386 BABIP that buoyed much of that production. In other words, one could expect Ruf to become a bit more… rough in the future (sorry). A quick search reveals that he had a higher groundball rate against righties compared to lefties, which doesn’t bode well for future success, and not much else. The critics win this round.

Here’s the thing, though – he wasn’t alone. It turns out that in 2021, right-handed hitters had a higher groundball rate against right-handed pitchers; conversely, they had a lower groundball rate against left-handed pitchers. You can see for yourself:

This is also true of left-handed hitters. Facing same-handed pitchers led to more groundballs, while opposite-handed pitchers led to, well, the opposite. The gap in groundball rate by pitcher handedness is greater for lefty hitters, though that may be influenced by the relatively few instances of lefty-versus-lefty matchups. Still, the difference, which appears on a league-wide scale, is significant enough to warrant an investigation. Read the rest of this entry »

The week before Christmas, I conducted an investigation into the Giants’ strange sinker-ballers. Logan Webb and Alex Wood enjoyed spectacular years, and they both did it using sinkers they released from a low starting point, which created a unique look for batters.

You probably didn’t read that article, and that’s okay. It was the peak of the holiday season. You were likely out in the world like me – seeing family, drinking eggnog-flavored coffee beverages, and generally making up for last year. My consumption of baseball media went way down, and I do this for a living.

As a self-interested person, I suggest you go back and read that article. I thought it was pretty good! More importantly, though, I’ve been doing more research into what the heck a “flat sinker” even is. The concept just doesn’t fit into my brain, and when that happens, I like to hit myself over the head with data until something clicks. So today, please enjoy some random things I’ve researched while trying to understand why in the world “flat” (approach angle) and “sinker” (pitch type) coexist. Read the rest of this entry »

For nearly a decade, you couldn’t go a week in the offseason without seeing an article about the American League’s dominance over the National League in interleague play. I know – I was already a rabid consumer of Hot Online Baseball Takes™ at the time and drove myself to distraction trying to find reasons to believe or disbelieve it. But it was interesting! The AL and NL split World Series roughly down the middle, but the AL kept winning interleague play and World Series games. Was it just a better league?

In 2018 and ’19, the trend flipped. The NL won the interleague season series in both of those years, which marked their first victories in that theoretical season-long series since 2002 and ’03. It had been quite a while, in other words.

By 2020, “who’s winning the interleague series” didn’t feel as interesting, and the unique pandemic-shortened schedule drove that point home even more surely. Due to geographically-divided schedules, there were nearly as many interleague games in 2020 as there were in ’19 (298 league-wide as compared to the standard 300 on the schedule every year since 2013), despite playing a 60-game season rather than 162. Not only that, but there wasn’t the usual rotation of opponents and rivalries. Instead, each division played its opposite-league counterpart. Read the rest of this entry »

Ah, sinkers. Wait three years, and the “smart” view of them will change. In the early 2010s, they were the coolest. A few years later, they were a laughingstock, a sure way to make your franchise seem old-fashioned. Between 2015 and 2019, the league abandoned sinkers (and two-seam fastballs, which I’m including in today’s analysis) en masse. In the former, pitchers threw 148,000 sinkers. By the latter, that number fell to 116,000. That trend is still ongoing; 2021 saw only 109,000 sinkers.

Despite the downward trend in usage, sinkers are cool again. When the league switched to Hawkeye tracking technology in 2020, the public could suddenly see the impact of seam-shifted wake, an effect that creates movement that previously wasn’t being measured. Pure transverse spin — like a backspinning four-seam fastball — is one way to create movement. Seam-shifted wake is another, and sinkers have it in spades, though they also generate plenty of movement from spin.

What does that word salad mean? Basically, sinkers drop and fade more than you would expect given the spin that pitchers impart on them. It’s not like sinkers started moving more in 2020 when cameras caught this effect, but quantifying something makes it easier to look for and teach.
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After a quiet 2020 offseason, and in advance of the ongoing lockout, the early 2021-22 free agency period saw a sudden burst of activity. Teams shelled out more than $1.5 billion in new contracts, a record-breaking pace. Not only did they act earlier in the winter than we’re used to, they also spent far more than last offseason. Is free agency fixed? We’ll need to dive into the data to find out.

See, “how much money was spent on free agents” is an inexact measure of teams’ spending appetites. Imagine an offseason where, due to strategic contract extensions and a wildly immoral use of cloning technology, the only players on the free agent market are 37 versions of Alcides Escobar and 25 copies of Jordan Lyles. Free agency spending would crater, and it would be hard to blame teams for it. It’s not as though you have to give the best player on the market a $300 million deal; contracts are, obviously enough, affected by the caliber of player signing the contract.

Rather than come up with some new form of analysis, I decided to use a methodology advanced by former FanGraphs writer Craig Edwards. The idea is straightforward: take players projected for 2 or more WAR by Steamer in the upcoming season, apply a naive adjustment for aging, and project how much WAR each free agent will accrue over the life of their contract. Like Craig, I applied some discounting for playing time projections. That lets us create expected $/WAR numbers for each year’s free agency class:

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