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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At the end of October, I wrote about the alterations José Urquidy made to his arsenal during the postseason, trying to estimate how much better or worse his pitches might have been given their velocity and movement changes. In that piece, I briefly touched on raw movement changes but mostly relied upon the vertical and horizontal approach angles (along with location and release point changes) of Urquidy’s pitches to try to fully encapsulate their movement. While the concept and value of vertical approach angle is rather intuitive, I figured it would be useful to go into horizontal approach angle here today and have fun with a little exercise.

This post is inspired in part by all that we have been able to grasp in the public sphere when it comes to vertical approach angle. Measuring the up-down angle of a pitch as it enters the zone is largely derived from the vertical movement measures we’re so accustomed to. Steep vertical movement on breaking pitches and “rising” four-seam fastballs in the upper parts of the zone have been coveted for a while now because we know those pitches are associated with whiffs and therefore success. Much less can be intuited by simply looking at the pitches with above average horizontal movement. Read the rest of this entry »

With last week’s lockout of the players by ownership, the league has frozen all transactions for the foreseeable future. That’s bad news — but it also makes this a good time to take a snapshot of team payrolls, because there are no new deals coming down the pipe to mess up the analysis midway through. As such, the following is an update on each team’s payroll as it stood at the start of the lockout. Here are our team-by-team RosterResource projections:

A few notes, some of which will likely be familiar to you if you followed past versions of this exercise written by former FanGraphs writer Craig Edwards. The above data counts salaries for 2022, not average annual values. It includes estimates for arbitration, as well as estimated minimum salaries paid throughout the season; our payroll pages currently use the 2021 league minimum, but that number could change in the upcoming CBA. The numbers don’t include incentive bonuses, or a few specific CBA wrinkles, such as the approximately $2 million that teams pay to players who aren’t in the majors but are on the 40-man roster or the roughly $16 million per team spent on player benefits. They also don’t include as-yet-unsigned free agents, naturally.

The Mets’ recent signing spree, combined with the Dodgers’ losses in free agency, has seen the two teams change places at the top of the payroll standings (somewhat surprisingly, the Mets finished as the second-highest spenders in 2021). All told, there are three teams (the Mets, Dodgers and Yankees) that are currently projected for more than $200 million in player salaries in 2022, the same number (and the same teams) as last year. Meanwhile, there are two teams (the Pirates and the Guardians) with projected payrolls below $50 million, one more than last year, and neither of those teams is likely to make meaningful free agent signings when transactions resume. Read the rest of this entry »

MLB’s plan to de-juice the baseball this year seems to have worked. Home runs were down in 2021 compared to the last couple of seasons, though not by so much as to warrant a complete shift in the game’s current offensive paradigm. Instead, run scoring — which remains heavily concentrated around home runs — decreased overall. Non-pitchers hit just .247/.321/.418 this year, representing the second-lowest batting average in the live ball era (1920-present and excluding 2020) but the fourth-highest isolated power.

In slightly de-juicing the baseball, MLB erased some home runs. But as we can see in the sudden drop in batting average, which is down nine points for non-pitchers compared to 2019, shaving off homers didn’t result in other types of hits. As I wrote in my second of two pieces analyzing early 2021 home run trends, these lost homers mostly just became outs. That explains the significant reduction in overall offense, even as the league-wide home run total remained quite high in the context of baseball history.

With the season now officially complete, it’s time to revisit some of those early trends to get a final estimation of the effect of MLB’s de-juicing. Of course, there is a significant, potentially confounding, variable that makes 2021 different from other full seasons and complicates our analysis: the midseason enforcement against the use of sticky stuff. I will try to account for that here, though it probably deserves its own standalone examination. Read the rest of this entry »

Every season, we brace ourselves for the inevitable decline of baseball’s stars of yesteryear. Unfortunately, we’re all getting older, and despite their rare talents and athleticism, major leaguers eventually lose production. But while each individual has their own rate of decline, generally speaking, we know a fair amount about how age affects hitters’ abilities: A typical player peaks around age 26 and gradually declines afterward in what we know as the age curve. For those fortunate enough to stick around into their late 30s. that decline becomes quite sharp.

The basis for the age curve is the difference between a player’s performance across two different seasons. The choice metric for hitters tends to be wRC+, because it’s adjusted for league average and should be less impacted by league-wide trends and fluctuations from one season to the next. The chart below shows an age curve for players using data from the last 10 seasons, preceding 2021:

The shape of the age curve makes intuitive sense, for two reasons. The obvious one is that the primary skills needed to succeed in baseball (eyesight, strength, agility, etc.) decline as the human body gets older. Another, however, is that players only remain at the big league level if they’re successful. Whether it be due to injury, a slump, or even a little bad luck, a decrease in a hitter’s performance is an inevitability before they decide to retire (or the decision is made for them). Read the rest of this entry »