Did Sinkers Make the Comeback That Was Promised?

Back in mid-February — a truly different time for all of us — I applied to work at Statcast as an intern, a position that was unfortunately canceled in mid-March. However, I wrote an answer to a question that I intended to turn into an article at some point during the season. At the time, I figured I might write it in May, but a delayed season meant a delay to my piece as well.

Who would like to consider the curious case of Alex Presley? His career was relatively muted; he played for five teams in eight seasons as a fourth outfielder, only once cracking 100 games played and only once posting an OPS over .800. His Baseball-Reference page has him sporting a White Sox hat despite never having played a regular-season game for the team. He had a .620 OPS across 55 minor league games in 2018 and was released before he could make his way into July. He has the ignoble mark of having the second-lowest career WAR of any MLB player born in Monroe, Louisiana, finishing sixth out of seven players (Chuck Finley laps the field, and Presley finished above only Wayne Cage’s 0.1 career WAR). But Alex Presley was never supposed to be a star; rather, he was the now-forgotten harbinger of the launch angle revolution.

In the past several seasons, launch angle has absolutely been all the rage. Being able to capture new data has made an impact on the scene due in large part to fascinating statistics such as pitch movement, exit velocity, improved defensive statistics like OAA, and launch angle. During that time, teams have been changing their exit velocity drastically as well. In 2015, the earliest year with Statcast data, the measured average launch angle for all of baseball was 10.1. By 2019, it was 12.2.

In 2014, Pirates pitchers, the leaders of the sinkerball revolution, allowed an average launch angle of only 6.9 degrees. Since then, only three teams have been below 7.0 (the Rockies twice and the Cardinals once), and in 2018 and 2019, only three were under 10.0 and none were under 9.0. Additionally, even though the Pirates led the league in Barrel% by over a percentage point in 2014, the top teams in Barrel% in 2019 were much closer to a league-average launch angle. The data makes it clear: Launch angle is certainly going up.

The next question is why. Back when I was first writing this answer, I vaguely recalled Presley — a player claimed off waivers in 2014 by the Houston Astros and then DFA’d about a year or so later — talking about raising his swing plane. After some digging, I found that Houston Chronicle article, written by Evan Drellich.

In this piece from 2014, Presley mentions previously being more of a ground-ball hitter, liable to scald the ball into the dirt hoping for singles before being told to change his swing mechanics. This didn’t work well enough for Presley to succeed, but the approach has touched more players than just him. As I’ve mentioned, launch angle has been rising around the league, and when players like Joey Gallo and Cody Bellinger utilize it to revamp their approaches, incredible things can (and have) happened.

(If you’re interested in Tyler Heineman, another player mentioned in the Presley article as having raised his swing plane, I recommend this interview of him from about five months prior. Check out the part where Morgan Ensberg says “Get naked on it” — seriously.)

With hitters adapting their launch angles, is it any surprise that pitchers have changed in response? In 2017, two articles came out regarding the sinker. Jeff Sullivan (right here on Fangraphs) wrote that baseball was moving away from the sinker, noting that fastball rates had fallen in recent years and fastball placement had suddenly jumped up to much higher in the zone — mainly to counteract hitters launching low balls into the atmosphere. This isn’t new to any baseball fan; it’s been hard not to notice teams like the Astros asking their pitchers to pump high-90s, elevated four-seam fastballs into the top of the zone, staying away from lower, slower pitchers.

Not long after, Matthew Trueblood of Baseball Prospectus wrote about the sinker being ineffective with respect to pitch tunneling, showing how much better four-seamers play along with curveballs and sliders, while sinkers and two-seamers fit better with changeups. In recent years, many pitchers have used pitch tunneling (with proponents such as pitching coach Brent Strom and All-Star pitcher Yu Darvish) to better serve their repertoire.

And what else started happening in recent years? While the fastball has fallen out of fashion — from 57.7% of all pitches in 2009 (and 55.0% in 2018) to a mere 52.5% in 2019 — sliders jumped up from a low of 13.2% in 2014 to 18.6% in 2019. In 2018, there were more sliders thrown than sinkers (around 17.1% each), even though there were 55,000 more sinkers than sliders in 2014, and in 2019, the number of sinkers dropped even further to a precipitously low 15%.

And really, we must talk about the difference between 2014 and 2019: For one, 2014 is remembered as a terrific year for pitchers as they sported a 3.74 average ERA. Meanwhile, pitchers in 2019 had an average ERA of 4.51. But at the same time, even though 2014 looked like a crazy year for strikeouts — K% had risen from 18.0% to 20.4% in 2014 — that same trend continued from 2014-19, reaching 23.0% last year. Clearly, the two years were not created equal.

All these things must, of course, be related. Hitters started changing the plane of their swings to hit two-seamers and sinkers better, and pitchers responded by throwing nastier pitches to increase whiffs. Home runs jumped up, but so did strikeouts; Gerrit Cole struck out 326 hitters last year, and Josh Hader had a K% of 47.8%, but more homers were hit than ever before. And because of the juiced ball, the way four-seam fastballs were valued was about to change.

Ben Clemens of Fangraphs did a deep dive on baseball moving away from the sinker in recent years. His findings were that, in a nutshell, teams had realized that fastballs actually were more valuable than sinkers, because even though fastballs were hit more often — and were more likely to be sent airborne — the value inherent in a more strikeout-friendly pitch outweighed the benefits of a pitch that put the ball on the ground. Especially in 2019, the whiff-happiest year on record, a pitch that was intended to induce ground balls and double plays just wasn’t getting the job done (Side note: singles + walks declined by about 14% between 2015-18, so even though a double play is more valuable than a strikeout, there just weren’t enough runners on first base to make the numbers work). One metric that jumped out to me was the vast disparity between wOBA on fly balls of sinkers and fastballs in 2014 vs. 2019. Most years, fastballs allow approximately a .350 wOBA on fly balls, with sinkers just a bit higher. In 2014, those numbers hovered around .250, and in 2019, sinkers allowed an insane .450 mark (with 4-seamers coming in around .400).

This, again, makes all the sense in the world. Fly balls were traveling farther than ever before in 2019, and pitches that were just too easy to make contact with — and, with launch angle higher than ever, were much more likely to be hit in the air — went out of style. Even as four-seam fastballs became far less valuable (due to, in no small part, the juiced balls), sinkers remained even worse (although much less dramatically than in years past). It was for good reason that Cole and Justin Verlander had obscenely high HR/FB% (both over 16%), but sinkerballers have routinely dealt with numbers that high, even without the juiced ball; Jared Hughes, who threw the highest percentage of sinkers of anyone in baseball last year, had a ridiculous 28.9% HR/FB rate. Is there any reason at all why sinkers would ever make a return?

In the 2019 postseason, the juiced balls seemed to suddenly disappear. Regular season home runs were routinely dying on the warning track, and the ball traveled about 15 feet fewer, on average, on fly balls. One player in that postseason was the 2019 Rookie of the Year, Yordan Alvarez. He was a terror for the first few months after his mid-June call-up, hitting 27 home runs in just 87 game with a wRC+ of 178 that would’ve been second only to Mike Trout had he qualified. But near the end of the year — and especially in the ALCS — it seemed as if he’d been figured out. He was fed a steady diet of balls in the dirt, and his uppercut swing — emblematic, one might say, of the 2019 season — ended up being his downfall. His OPS against the Yankees was a mere .170, and he struck out in half of his plate appearances. But against the Nationals in the World Series, he changed his approach. Instead of going all-or-nothing, he started trying to hit more line drives. He only collected one extra-base-hit — a home run — but he added six singles and walked twice as often as he struck out, adding up to a team-leading OPS of 1.112. Of course, he wasn’t doing what he was supposed to do best, but someone’s got to get on base, right?

Back in August, Tom Verducci warned of the death knell for the fastball, and fastballs as a whole have dropped below 50% for what I can only assume is the first time ever. Let’s check in on our top sinkerballers in baseball. Aaron Bummer, he of the 80+% sinker usage, probably doesn’t count because of the unparalleled 8.2 inches above average of drop on his sinker, but he has yet to allow a home run this year (or even a barreled ball). Zach Eflin, the starter throwing the most sinkers, has jacked up his sinkerball usage this year to above 50% after barely breaking 20% last year. His HR/FB rate is down five percentage points. Framber Valdez, who throws the third-most, has cut his HR/FB rate by more than half, even as his average Launch Angle on sinkers has increased since last year.

These stats are admittedly a bit cherry-picked — it’s less black-and-white in general — but check out this leaderboard, which shows sinkers as being far, far more valuable than they’ve ever been league-wide (versus being the worst pitch in baseball last year), even as they fall out of favor. Four-seam fastballs, meanwhile, are less valuable than ever (last being above average in 2014).

Is this all a sample size problem? Possibly. Launch angle continues to climb even higher, and Barrel% has gone up as well. But don’t get fooled by the fact that HR/FB rate has stayed the same following last year’s high. Exit velocity is actually a little weaker than last year, and line drives just are not leaving the park as often. While four-seam fastballs keep getting crushed, grounders are getting gobbled up even more than usual (and, it should be mentioned, singles and walks are both up in 2020), and the sinker looks like it should be (groan) a pitch on the rise. The question now is: will it?