Attack Of The Sliders, Part 2: Hitters Who Are Hanging, And Then Some

When I last left you, I spoke about how sliders are taking the game by storm. We’re witnessing the biggest year-over-year jump in the pitch being thrown in more than a decade and the reasons are pretty cut and dry. They get more swings and misses than any other common breaker, and, considering the rate at which the ball is flying out of the park, pitchers are incentivized to optimize for strikeouts more than ever.

As if it were baseball’s form of natural selection, some hitters are handling it better than others. Jonathan Schoop, Leonys Martín, Corey Seager, Ozzie Albies, and Byron Buxton had all seen at least a five percent jump in sliders faced. And they’ve struggled against the pitch to the point where their performances may give us pause moving forward. Enough time has passed that we can reset our parameters for considering who’s doing well.

Coming into the weekend, 87 hitters had faced at least 150 sliders. Of that group, 16 had seen at least five percent more than they did in 2018. Here are the eight who have handled them best:

attack of the sliders 2.png

Whether or not any of these hitters have been historically good against the slide piece isn’t necessarily interesting. The difficulty the pitch poses combined with the uptick in the amount they’ve each seen it would lend itself to additional struggles. And in many ways, the way they’ve performed against it this year tells the story of their production. For point of reference moving forward, consider how the population of 87 who have seen at least 150 sliders so far this year had performed, on average:

  • SL Whiff%: 16.6
  • Take%: 53.3
  • wOBA: .287
  • EV: 83.1

These data points jive pretty well with what we saw in Attack of the Sliders, Part 1. They let us sift the group of eight above into two groups — ones named Yandy Diaz, and ones not. Let’s start with the others first.  

the good guyz

Most of these guys hit the slider hard. All of them are below average at letting it go by, and, accordingly, whiff on it more than average. But by and large they all make their contact count against the pitch as much as they can, and their performance against sliders is contributing in no small part to their total value this year.

For Soler and Santana in particular, their performance against sliders so far in 2019 might be a key to what’s keeping them in the lineup. They rate out as a couple of the worst defenders amongst these eight players so the weight of their relevance sits on their bats. What’s most interesting is that they’re reaching success in different ways despite similar results. They have nearly identical plate discipline, but Santana makes nearly 18% more contact on pitches out of the zone than Soler. That would lead us to believe that contact he makes generates his lower exit velocity if he isn’t barreling the ball, but still putting it to places that can’t be defended. When it’s left in the zone, no one connects more than Soler out of this bunch. His top 25% exit velo against sliders supports his ability to swing freely but really lock in on the stuff over the plate.

Javy Baez continues to make an extreme contact profile work, and he’s so good that it isn’t just about taking advantage of mistakes. He’s one of the worst hitters in the league at taking a pitch — he swings at more than 90% of qualified hitters — and yet, he’s in the 85th percentile in wOBA and nearly 80th percentile EV amongst hitters seeing the biggest increase in sliders. With his plus defense, this peak under the hood illuminates why he’s been the most valuable of the bunch so far.

The two Yankees on the list also tell an interesting tale. After all their injuries, New York is doing the unthinkable and pacing the AL East. Voit’s performance last year made it highly likely that he wasn’t a flash in the pan, and he’s officially taken the Yankees first base job and run away with it. Being able to hang with sliders and other breakers while crushing everything else appears to simply be his M.O.

Frazier, meanwhile, requires a bit of an asterisk. He only had 41 scattered plate appearances last year, but the big increase in sliders over more playing time in this campaign suggests a tremendous amount of immediate respect from opposing pitchers. With how hard he hits sliders, we might be able to expect a better overall performance against them moving forward, because as basic as it sounds hitting the ball hard is still a huge indicator of productive play. It could also make the Yankees somehow more difficult to face. He almost embodies the way they’re winning this year — an unheralded guy or one whose sheen had worn off for various reasons, coming out and balling.

Reyes — affectionately known as The Franimal — is the healthy counterpart to San Diego’s highly likable Big Boi outfielders who can absolutely crush the ball. He has some of the worst plate discipline against sliders but encouraging results when he does connect. At just 23, he’s showing a ton for the Padres to get excited about. Sure, the team is 10 games back in their division, but they’re also two games over .500 and on the precipice of arriving as competitors. If Reyes continues to grow in his ability to track breaking balls at the plate, he could help propel them forward. Even if he merely stays the same, he’s going to continue to have a positive impact.

Avi Garcia offers another fascinating look at Tampa Bay’s ability to acquire and develop players who seems to have enormous holes in their game. He’s on pace for the best season of his career, much like fellow teammates Tommy Pham and Yandy Diaz, who were similarly cast off from their former clubs. He’s been up and down against the slider throughout his career in the Majors but has clicked in 2019. His plate discipline is still suspect, but the last time he was this good he was worth more than four wins for a cellar dwelling White Sox team. Another performance like that on a team pushing for the playoffs is going to be one to watch.

And that brings us to Yandy.


Diaz has seen more sliders than most hitters, spit on them more than anyone who’s seen as big an increase, whiffs less, and hits it harder than nearly everyone. Sure, his ability to drive the ball hasn’t resulted in the best wOBA against sliders, but the Rays have already gotten him to hit as many homers this year as he has in the last two years combined. That’s far from a baby step. His defense is middling but his long-expected ability to hit is finally bearing fruit. He’s a prime example of how the Rays keep creating formidable matchups for their opponents in the most creative (cheapest?) ways possible.

The slider is probably here to stay. So far, these hitters are staying with it, and I will, too. Stay tuned for more updates on how the pitch is impacting the game at the highest level!

Slider data from Statcast. All other data from FanGraphs. Feature photo from Chris O’Meara/AP


Attack Of The Sliders, Part 1: Struggling Hitters

The most recent advent of baseball has brought with it a fervor for sliders across the league. Others have written about it — Matthew Trueblood wrote last September that pitchers were choosing sliders over sinkers, while just recently Eno Sarris noted that it’s more severe now when examining the struggles of Bryce Harper. It’s true. We’re on track to witness the largest year-over-year jump in sliders since 2010-11. They’re now accounting for 18% of all pitches and the league is on pace for about 8,000 more sliders thrown than last season. If we were talking about White Castle sliders, you’d pretty much be dead.

It makes sense that pitchers are chucking more sliders. It’s the pitch generates the most whiffs of any offering thrown with regularity. It makes sense that the pitch is usurping the sinker, because the sinker generates the least amount of whiffs. Every team has a guy who can throw gas at this point, and now half the league is leaning into it the slider as a primary breaking pitch as hitters and pitchers alike optimize for the best possible outcome. And it’s affecting some more than others.

Through this past weekend, 149 hitters had already seen at least 100 sliders. Of those, 100 had seen more than the average amount compared to their peers, but some guys are really getting beraged. Here are the 10 players who are seeing the biggest jump in sliders faced, of the group who’s seen the most sliders so far this year:

attack of the sliders

Certainly, this is a talented group. But it’s also equally as weird. I’m not sure you’d put them together for any particular reason outside of maybe age, and even that only regards about half of them. Even here, the closest thing they all have in common is a bad whiff rate at sliders. Their overall performance against the pitch, though, lets us split them into two groups of five. Today, we’ll take the bad news.

bad sliders

Before delving into the case of each player above, let’s keep in mind the average rates for each stat above for this entire group of hitters:

  • SL Whiff%: 16.8
  • Take%: 52.3
  • wOBA: .285
  • EV: 83.2

These points give us some context for just how much trouble the slider is giving each of these five guys.

Schoop signed a one year, $8.5 million prove-it contract with Minnesota over the winter. So far, the returns are good and he’s definitely rebounding from a woof-worthy stint in Baltimore. He’s showing the most power of his career, as his .234 isolated slugging tells us, and isn’t necessarily lucking into his success. It’s hard to say if sliders are keeping him contained or portend tougher times ahead, but he’s in the bottom 20% in everything but wOBA against them. It’s not a stretch to think the low exit velo and hack-happy approach leaves him exposed.

Leonys Martín is tied with Jordan Luplow as Cleveland’s best outfielder, though Luplow has played in 16 less games. Collectively, the group has actually been worth -.1 wins so far this season, though, so it’s not a terribly meaningful title, anyway. Martín isn’t offending anyone, but his inability to lay off sliders may make for predictable ABs as summer wages on. Despite this, his ability to make just enough quality contact to be definitively average will probably keep him in the lineup, as Cleveland’s front office appears aloof to the dearth of talent they’re leaving to patrol the outfield.

Pitch Info actually has Corey Seager as a positive performer against sliders for every season before this one. Maybe he’s not used to using his body as a baseball player again after a long injury and rehab process from last season, or maybe this is just a blip on the radar. But the drop in performance against sliders is worrisome because of the volume he’s seeing. He’s always had a take percentage against the pitch that’s similar to this year’s, but he’s also always been able to drive it much better. This feels like the kind of thing that could make or break a big moment or two in the Dodgers’ season.

Ozzie Albies…hmm. Albies is becoming more and more curious in the early stage of his career. He came up with a reputation of being able to control the barrel of his bat and take a walk, then hit the big leagues and swung at everything, showed impressive and unexpected power, then started to whiff. A lot. Simply having the major league experience he does at this point still bodes well for his long-term outlook. Atlanta is in a curious position, though. They chose to lean heavily this winter on a core that appeared to arrive early instead of using that performance as a reason to buy complementary pieces sooner. Albies is a big part of that choice, but right now everyone is left to take his solid all-around game and hope the upside shown by his ability to discern the strike zone catches up to his ability to drive the ball when he finally does square it up.

Buxton is another Twin who’s enjoying a fine rebound after a dismal 2018. Out of the guys who have seen the most sliders this year, he’s tied with Brandon Lowe for the highest fWAR. If he maintained his current rate of offense — he has a 115 wRC+ — and paired it with his elite defense, he’d be a huge piece for the Twins as they continue to muscle through the league. But we know he’s prone to big slumps and any additional increase in sliders could spell some trouble. Slight regression from a few guys in Minnesota could mean a lot more in a wacky AL Central, and, perhaps more than usual, the games will start to break more and more for or against them based on just a few centimeters.

Whiffs are increasingly inseparable from baseball. The guys featured above all embody that, and emphasize how important it is to make your contact count. So far, they’ve been vulnerable, despite being quality contributors. Whether it changes or not could have a pronounced impact on their final lines for 2019.

Stay tuned for part two of this story, when I’ll explore five guys excelling against the slider despite seeing a bunch more of them!

Slider data from Statcast. Pitch values and WAR from FanGraphs. Feature photo John McCoy/Getty Images

The Reds Pitching Staff Is On A New Level: Atop Baseball

The nature of change often makes it seem as though it’s happened overnight. We aren’t particularly good at seeing the tiny, consistent changes that build up over time when it comes to seeing it in others. We aren’t particularly patient enough to enforce those same tiny, consistent tweaks when we attempt to change ourselves. And beyond that, it’s more fun to subscribe to the idea that someone went to bed one night one way, and then woke up the next day completely different. It’s conveniently inspiring and hopeful.

Nonetheless, real change happens with quiet commitment. The Cincinnati Reds pitching staff so far in 2019 is proving to be a great example. Last year, they were the fifth-worst in all of baseball. So far this year, they’re tied with the Tampa Bay Rays for the best in all of baseball.

Reds data

The data only go as far back as when games started at the end of March. But to appreciate when the Reds really started to implement change to their pitching approach, we have to go back to last October when they hired away Derek Johnson from the division rival Brewers. Johnson came to Cincinnati with a reputation as one of the best pitching coaches in the league. He spent the last three years in Milwaukee; before that, he was the minor league pitching coordinator for the Cubs for three years, and before that, he was the pitching coach at Vanderbilt University from 2002-12. Those are all in their own ways forward-thinking organizations of which Johnson was integral part.

He’s not the only improvement the team made. In January, the Reds hired Caleb Cotham as an assistant pitching coach. Cotham was coached by Johnson and was teammates with Sonny Gray at Vanderbilt. He has Major League pitching experience, has trained at Driveline, and most recently worked for the Bledsoe Agency while focusing on player development.  To get a sense of his approach, consider this picture he tweeted in January 2018:


Those baseballs are marked up to aid the use of a Rapsodo, to help show a pitch’s spin axis and provide cues for pitchers as to how to manipulate the ball as it leaves their hand. The Reds joined the revolution this offseason and began using Rapsodo in spring training, and made sure they had staff that not only wanted to implement it, but knew how to get the most out of the cameras that can provide thousands of slow motion frames per second.

That’s what the team has done on the coaching side of things, but the games and execution are still left to the players. Big changes were made there, too — Sal Romano, Matt Harvey, and Homer Bailey are no longer on the 25-man roster. They recorded the second-, fifth-, and sixth-most innings for the Reds last year and just 2.4 fWAR combined. Others who contributed somewhat regular innings, like Matt Wisler, Austin Brice, Dylan Floro, Jackson Stephens, and Brandon Finnegan, are also either no longer with the organization or are in the minors.

The Reds have fortified their rotation with Sonny Gray and Tanner Roark, and moved Robert Stephenson to the bullpen full time. So far, they’re the best pitchers the Reds have who aren’t named Luis Castillo, in large part thanks to a serious commitment to sliders. Gray isn’t trying to throw his for strikes as he was with the Yankees, and he looks like his old productive self. Roark is throwing the slider an additional 12% from last year. Stephenson has gone mad and is throwing it 20% more than in 2018. The early returns have clearly been favorable, but was solving the problem really just about the Reds getting new coaches and shuffling the deck?

Animated GIF-source (3)

All of these heat maps are from the catcher’s perspective. As a staff, Reds pitchers are demonstrating better command almost across the board. Fastballs are more clearly up and to the first base side. Sliders are extremely crisp, painting the low, first base-side corner and seemingly refuse to leak more into the zone. Curveballs aren’t being left in the heart of the plate. Changeups are being pounded with more authority to the low corner on the third base side. Two-seamers are working more to the lower third of the zone.

The team is also employing them far less, having accounted for anywhere between 5-10% less of the staff’s total offerings, depending on which pitch classification system you use. Over the course of the season, that’s roughly a thousand less sinkers, at least.

The two-seamer is the pitch that gets the least amount of whiffs. Trading them for literally any other pitch is a net win in that regard, which might help explain how the Reds have managed to maintain the amount of walks they give up while adding 20% more strikeouts over last year. We’re at a point where pitchers and hitters are each optimizing for the best possible outcome: strikeouts and homers. Going for more whiffs as hitters are already primed to swing and miss because they’re going for extra base hits is a no-brainer, but the Reds appear to have had more room to improve in this area than most teams, and have done it as much as possible since last year.

The improved command has lead to improved efficiency, too. Reds pitchers have thrown the eighth-fewest pitches in the Majors. From 2016-18, they never ranked better than 16th by that measure. Throwing fewer pitches doesn’t necessarily correlate to automatic success — for example, the Yankees threw more pitches than nearly everyone last year but their staff was also better than every team except the Astros — but in this instance, it’s clear that the Reds’ efficiency is representative of a big part of their ascent so far.

It started with one coaching hire, and then another. And then they added new tech that complements old knowledge and relationships. Since then it’s been about executing each pitch with more authority to places that are harder to hit it. The Reds are five games under .500 in what could be baseball’s toughest division, and yet they’re in the midst of a turnaround on the mound that’s unprecedented. Tune in to be a witness. 

Heat maps from Statcast. All other data from FanGraphs. Feature photo by Joe Sargent/Getty Images.

Quick Hits: Jacob deGrom and Sam Gaviglio Have Changed Their Pitch Mix

I’ve got more ideas for pieces than I might have ever had, but I’m also in the midst of moving. I can’t flesh out all of them at this moment, but below are some worthwhile tidbits for you to enjoy.


Sam Gaviglio is working out of the bullpen for the Blue Jays this year and it’s going really well. He’s one of only 20 relievers to register at least 10 innings pitched so far — 305 have recorded outs, per FanGraphs — and there’s good reason. He has a 26% K-rate and a 21.4 K-BB rate. The only other times he’s done that were 2011, in four innings at Low-A; 2013, in nine innings in rookie ball; and 2018, in 29 innings at AAA.

His last stint in the minors would suggest some change, but he came up and produced a sub-par whiff rate for Toronto in nearly four times as many innings. As a guy who can barely break 90 mph, it might be fair to consider if this is just a flukey April performance. But he’s made a real change to his pitch mix this year. 


Gaviglio’s primary pitch has become his slider, which is creating whiffs at a 26% clip. That’s nine percent better than league average. Last year it was just above average, at 19%. He’s tightened up the shape of it, but the results are a while off from us being able to fully buy in on his performance so far. It seems legitimate, though. The benefit really seems to be from trading a pitch that doesn’t get any whiffs for almost anyone — the sinker — for the one that generates the most.

Gaviglio’s got a spot in the bullpen that seems to suit his newly adapted skill set. He has a pitch that can get hitters to miss and one that they can drive into the ground, and he’s prioritizing them in that order. And remember, most guys throw harder when moved to a relief role because they can spend more energy on each pitch without having to worry about turning over the lineup multiple times. Maybe we even see a velo bump out of him at some point that helps his stuff play up even more. He’s not getting a lot of buzz right now, but he’s pretty intriguing.


Everyone is entitled to a bad day, even when you’ve had a record-tying amount of consecutive good days. But now Jacob deGrom has had two uncharacteristic starts in a row and we haven’t seen that kind of performance from him since May of 2017. He’s gone just nine innings in his last two starts and has given up nine runs, five homers, and  five walks, to go with 12 Ks. His velocity is fine. The ball is juiced again. But there’s still some weird stuff happening under the hood.

One is that his pitch mix has changed. He’s siphoned away from the pitches he uses least — his curveball and two-seamer — and replaced them almost all with four-seamer, which he’s now throwing more than 50% of the time. He’s never done that in his entire career.

His nasty slider has also straightened out. As a dominant pitch, it’s never had a ton of drop or bite, but now it’s lost about a half inch on both horizontal and vertical break. The results have not been pretty. Batters are slapping it to the tune of a .474 wOBA. The league average hovers slightly above .260 and last year, batters only squeaked out a .206 wOBA against deGrom’s. These numbers are far from stable — his only has six hits against it — but pitch shape actually stabilizes really fast. It’s odd.

DeGrom is also throwing the slider 1.3 mph faster, and he isn’t spotting it well. It’s going more clearly out of the zone instead of painting the edge. His fastball has also been all over, and it’s hard not to wonder if there’s a tiny mechanical issue going on.

Animated GIF-downsized_large

Below are two stills from right before deGrom brings his arm up as he delivers the ball to the plate. They’re both from Citi Field. On the left is from 2018, and on the right is from this year. In each, he’s throwing a slider.


Maybe I’ve stared at this too long, but it seems like he was more open to the plate last year, and that he’s more compact this year. We can see this in his throwing hand being closer to his body and his hips being slightly more closed this year. At 6’4″, he’s got big levers, and maybe he isn’t optimizing them right now. These are tiny details, but we all know that tiny details can scale big in this game.

You can look at the clips here and here and play it slowly for yourself if you’d like. It’ll be worth keeping an eye on deGrom moving forward for reasons we probably didn’t expect.


That’s all for now. Keep your eyes peeled for a similar post on hitters as we settle into our new place. Until then, may you consume as much baseball as possible.

All data from Statcast unless specified. Feature photo: Kathleen Malone-Van Dyke/NewsDay

The One Stable Stat We Have Is Telling Us About Potential Breakouts Already Happening

Welcome to the start of the 2019 season. We’ve got some interesting stuff going on already! The Yankees are missing an entire starting roster due to injuries. Christian Yelich is so hot at the plate that he might actually spontaneously combust. Tim Beckham is your fourth-best player in the entire league. Things have been wild! By and large, they also don’t — and can’t — mean much because the sample size is so small. Almost.

Thanks to work by Rob Arthur, we know a single batted ball in the air can be predictive. Basically, the idea is that a single exit velocity reading can purely measure how strong a hitter is without having to attempt to account for noise like bad fielding or a kindly gust of wind like other stats might. That strength correlates pretty well with OPS, giving us a reasonable measure of what we might be able to expect from certain hitters moving forward, almost regardless when they rip one like this.

So far this season, 15 hitters have hit two line drives or fly balls at 109 mph or more. Data points can often seem awkwardly arbitrary, but this one isn’t. As Arthur explains, it’s the point at which players gain a bump of six points of OPS per each additional mph they hit a ball. We’re looking at line drives and fly balls because they’re the hardest to defend. About half of those 15 guys are ones who are more established as stars or at least serious threats in the league: Bryce Harper, Nomar Mazara, Gary Sanchez, Joey Gallo, Nelson Cruz, Jose Abreu, Mike Trout, Hanley Ramirez. The other half are not. Here they are, with the rate at which they knocked a ball in the air at 109+ mph last year:


The highest fWAR production of any of these players in 2018 was Harrison Bader’s 3.5, which probably has to do more with his excellent defense at a premium position than his 106 wRC+. Nobody else broke two wins above replacement, though Voit almost did in just 47 games because he played like a madman in September. Mancini and Buxton actually managed negative fWAR of -.2 and -.4, and Buxton managed that in just 27 games. Voit and Alonso offer some later and very late development sheen, but outside of that it’s a rather motley crew.

Here’s how they’re airing it out so far this season, barely more than a week into the season.

Mashin 2

The Mets chose the middle ground between holding Alonso in the minors last year and further manipulating his service time by breaking camp with him in the Major Leagues. Bully for them. He’s been exactly as advertised, with a K-rate over 30% but seven RBI and an isolated slugging about a hundred points better than league average. The average of projection systems ZiPS, Steamer, and THE BAT see him having a .748 OPS the rest of the way, but the way he’s hitting early suggests he might not have much trouble exceeding that.

Voit has one more big knock despite seeing 80% fewer pitches so far, and it really seems like the Cardinals are having a hard time knowing the offensive talent they have between their nonchalant send-offs of him and Tommy Pham. He’s been similar to Alonso, but with less Ks and more than two times the amount of walks in the early going. The Big Three project him for a .795 OPS from here on out, with heavy regression in his slugging since his torrid September last season. It wouldn’t be terribly surprising to see him beat that, though.

Buxton has been the Dr. Jekyll to his Mr. Hyde so far, but also left the Twins game on April 3 with a back contusion, so he’s really staying on brand here in the early going. Mancini is a quarter of the way to his 2018 total for smoked line drives or fly balls, despite seeing only a tiny fraction of the pitches. His three percent walk rate is also about half of what he usually produces. That’s not a reliable rate yet but it’s worth considering that Mancini has just run into a hot streak to start the year.

Franco, Bader, and Tellez off the most intrigue, especially measured against what ZiPS, Steamer, and THE BAT project for them moving forward. Franco is projected for a .781 OPS the rest of the way, providing about another 25 homers, 63 runs, and 84 RBI. He’s walking a hilarious 26% more than he’s whiffing right now thanks to a league-leading six intentional walks. Part of that is because he’s batting eighth and is an easy route to the pitcher, but part of it is because he’s shown himself to be a legitimate threat to make pitchers look really, really bad so far. The plate discipline can’t stick at the current rate but if it’s an indicator of a true adjustment — and it might be, as he’s swinging a little less at junk low and away so far — it might be tagteaming with this new drive to smoke the ball to help Franco shoot past that projected .781 OPS.

Tellez is expected to produce a .750 OPS moving forward and is maybe the biggest wild card of these three. He had some hype as a prospect with lots of pop but had a terrible year in his personal life last year as his mother passed and he fell off a lot of radars. He squeezed into 23 games in the Majors at the end of the season and showed that pop, and now he’s doing more of the same but with way better plate discipline. He’s a Blue Jay down to the tee: grips and rips and gets results through bombs. He’s projected to break 20 dingers and a shade under 70 runs and RBI each, but, like Franco, if the plate discipline sticks a little with this ability to drive the ball, he could push past those with relative ease.

Bader looks like he’ll push another 20 home runs but only another 60 runs and RBI each or so. His projected OPS is a shoddy .701. That was folding in the Bader we knew before he matched the two pitches he smashed at 109 mph or better last year in just four percent of the pitches so far this season. He’s also batting in the lower third of the order and might be hard to keep tamped down there if he keeps swinging like he has early on. If there’s a Vegas line on his OPS, take the over.

The plate discipline referenced above may not be fully stable for another month or so at least. The counting stats may be largely subject to game situations. But when we’re breaking down what produces them by just how hard a guy is mashing the baseball through peeking at exit velocity, they’re all showing upside we can buy into now. Get ready for the headlines.

Exit velocity and pitches seen data from Statcast. All other data from FanGraphs. Feature photo Rick Scuteri/AP

Brad Peacock Might Finally Have An Answer For Lefthanded Hitters

Brad Peacock has been a lot of things in his career. A near-afterthought as a draft pick, a top-50 prospect, a starter with an unsightly walk rate, injured with bone spurs near his spine, a nifty reliever, a great swingman…they’re all apt descriptions of the various phases he’s experienced. This year, he’s back in the rotation for the Astros as they’re primed for another season of success. Whether in an upswing or a downturn, though, lefty hitters have always been a bugaboo for him.

He came into 2019 sporting a wOBA against lefthanded hitters that was 29% worse than the average righthanded pitcher since he came into the league. I wanted to round that to 30% for the sake of convenience, but then I checked how Peacock has performed against same-handed hitters compared to other righties in the same time frame. Get this — he’s been 29% better at limiting quality contact than his peers. Talk about wild!

But back to how he fares against lefties. He has a three-quarter arm slot and his best pitches — his fastball and slider — aren’t necessarily ideal to go to battle with against them. With that in mind it’s understandable that he could have his limitations; that his ultimate effectiveness might be limited by the same things that got him to the Majors. Just consider what he’s thrown when facing a lefthanded hitter through his career:

peacock v lefties career
There are a couple clerical-type things to note here. One is that we could merge Peacock’s two-seamer (FT) and sinker (SI) into 229 total pitches. Even if we want to split hairs and distinguish them from each other, odds are infinitesimal that Peacock was trying to throw two different pitches. It’s just a pitch classification quirk. The other is that anything thrown by a pitcher less than about 10% is something we don’t need to sweat. It probably isn’t offered enough to really buy into the data it produces. So we can eliminate the two-seamer as a whole to get a closer look at how Peacock really approached lefties from the time he debuted in MLB through last year.

That leaves us with a four-seamer, a knuckle curveball, a slider, and possibly a changeup. Based on usage, let’s draw our focus tighter to just the breaking balls. Here’s where he located them:

peacock HHEEAATT

That’s from the catcher’s perspective. He alternated location with each, sometimes trying to get chases low and in and sometimes trying to backdoor them over the plate. They’re distinct pitches and that’s usually good. But in this case, maybe not so much. Peacock’s curveball has always dropped between six and 11 inches more than his slider. Meanwhile, its side-to-side movement shrunk from a four inch difference with the slider to less than an inch in the last two-plus seasons. Locating the pitches in different spots could have given lefty hitters the chance to distinguish the break on each pitch, line it up and drive it, or spit on it and wait for a fastball. With all that deep yellow outside of the zone above, there was probably a good chance for a walk, too.

In his first start of 2019, he changed things against lefties. To the pitch mix!

peacock peeitch meeix
Ok, so let’s ditch the two-seamer/sinker amalgamation. Let’s also ditch the single cutter (FC), because it was probably just a bad slider. We can take or leave the five changeups, and since we already left them earlier, we’re going to do it again. We’re going to continue focusing on only the four-seamer, the knuckle curveball, and the slider.

The first thing that jumps out is the fastball is down below 50% usage. The next thing that sticks out is the breaking ball preference has flipped. By flipping the script, Peacock got four called strikes on sliders to lefties in his 2019 debut, plus one whiff. The lefties let the curveball go and it became a ball half the time. 

There’s one more thing about how Peacock employed his breaking balls against lefties to start the season. Here they are in heatmap form from the catcher’s perspective again:

peacock heat

Both pitches fell to the same lower, inside corner. With the side-to-side break less than an inch apart from each other, and the curveball dropping more than an additional 10 inches, Peacock used them in tandem to cause fits for lefties.

Think of this with the heatmap as an aid. The pitches most frequently fell to the black dot below the zone, but the pitches that created the gradation of maroon out to orange up and into the zone are the ones that made it so hard for the hitter to decide whether to swing.

You might be thinking, “Big whoop. The Astros played the Rangers in Peacock’s first start. They stink.” You wouldn’t be wrong. They’re projected to win about 75 games, give or take a few. But Texas offers some dangerous lefties. Nomar Mazara, Joey Gallo, Rougned Odor, Shin-Soo Choo, Asdrubal Cabrera, and Ronald Guzman combined to go 2-for-14 against Peacock. The lineup was stacked with established lefty big leaguers (save for Guzman) whose wOBA was between average and 50% above average against righties as recently as last year, and they were collectively helpless. 

The season’s about a week old. What’s happened so far is by no means an indicator of what will continue to happen. But Brad Peacock might have changed his approach to lefties and that could be a big deal. It might not solve his times-through-the-order problem, where he’s 75% worse than his peers the third time seeing an offense. He’s also 25% better than them when seeing hitters the first and second time, though, so an uptick in efficiency could produce some scary-good results. The Astros have pitchers in the system like Forrest Whitley and Josh James, plus others, who could eventually take Peacock’s rotation spot. For now, he’s locked in, and might have a new trick up his sleeve to help keep it that way. 

All data from Statcast unless otherwise noted. Feature photo Ron Schwane/Associated Press.


“Player development doesn’t stop”: Sam Fuld on how sneaky hard it is to become a better player

This winter, I had a conversation with Sam Fuld, who is currently the Major League Player Information Coordinator with the Phillies. He was on his way back from a Type-1 diabetes camp he runs in partnership with the University of South Florida, and prepping for spring training. We talked about everything baseball from how he wished he kept it simpler in his playing career to finding better ways to practice to using different pitcher types as models for defensive positioning. But one part of the conversation keeps floating to the forefront of my mind.

Every year, we’re treated to players who seem to come out of nowhere to produce like stars. Just last year, Patrick Corbin tweaked his breaking balls and became nearly unhittable. Brandon Nimmo became so productive by adding power to his on-base ability that the Mets couldn’t find any more reasons not to play him. In 2017, the Yankees saw Luis Severino become an ace as his slider evolved and Aaron Judge produce power that matched his colossal size. Jose Ramirez created runs 50% better than ever in 2016 and has maintained that production after being previously evaluated by many to be a utility man or bench bat at best.

Now these guys are adamantly among the the most productive in the game. In the seasons before they broke out, they combined for 4.1 fWAR. Most of that was from Corbin, who was a perfectly fine pitcher, if not a household name. In their breakout years, they combined for 29.4 wins. As a group, they went from inspiring bathroom breaks to awe, seemingly overnight.

It can be easy to have that impression about players because we have a tendency to equate “Major Leagues” with “finished product.” It’s a reasonable enough assumption — after all, how often does one reach the pinnacle of their profession and then get drastically better? The thing about that thought, though, is it assumes that peaks are static. Realistically, “player development doesn’t stop. It’s not a minor league thing,” Fuld says.

The sentiment becomes easier to appreciate when remembering how more data seems to flow into baseball decision-making every day. But it’s important to distinguish the role that data has. Just existing doesn’t mean it’s going to jumpstart progress. Talking about it doesn’t mean it’s going to be applied correctly. Buying into it doesn’t mean you know exactly what’s going to happen, because “for every action, there is often some sort of unintended consequence,” tells Fuld. He continued:

“[I]f we’re trying to get someone to throw his dominant slider more often, maybe throwing it more will make him lose feel for one of his other pitches. Or if we tell a hitter that he should look for fastballs in the lower half of the zone because that’s where he does most of his damage, this might make him more susceptible to breaking balls down out of the zone because that’s where his sights have changed to.

Let’s stick with the pitching angle here, and look at Nick Pivetta’s 2018 to get a practical understanding of what Fuld is saying. Pivetta came into the year with some helium and ultimately produced nearly three wins, but had ups and downs as his walk and strikeout rates fluctuated.

Pivetta mix

Pivetta’s got a diverse arsenal. Each of the last two years shows us he has three legitimate offerings and at least a couple show-me pitches. The big difference is how he traded four-seamers for other pitches in 2018, mainly his curve. That’s because his curveball is really good. It has a ton of tumble due to having spin that’s better than 90% of Major Leaguers. He knows how to keep his wrist locked and wrapped around the ball when snapping it off, leading to lots of useful spin that creates drop. So throw it more! Throw it early! Throw it whenever! Great things will happen!

Or rather, great things could happen.

Pivetta breakers combined

The top image is the vertical drop on Pivetta’s breaking balls in 2018. His curveball continued to tumble hard, sometimes having as much as 10.5 inches of drop. His slider was a tighter pitch, with up to about two-and-a-half inches of drop.

The bottom image is the horizontal break on the same pitches. Each tended to move to his glove side, between seven and nine inches for his curve and between three and six for his slider.

Overall, the different movement on the pitches kept them distinct. But there’s one thing from the images above that we haven’t talked about — that maroon line, which sparked into existence in July and grew through the end of the year. It’s labeled here by Brooks Baseball as a cutter. It took on roughly the tight vertical and glove-side movement of his slider, but was off by a couple inches for each. It was also about four mph faster. It was awkward.

Pitch classification systems aren’t always in unilateral agreement over what a pitcher actually throws, but Baseball Savant didn’t even register Pivetta as throwing any cutters last year. Between that, the extremely low usage, its sudden July “introduction,” and the new reliance on his curve, it’s possible he was just throwing bad sliders. He could’ve lost the feel for it as the season waged on — an unintended consequence of leaning more heavily on his best pitch. For 2019, one of the biggest things that could help Pivetta continue to make progress could be keeping his pitches distinct so he’s more comfortable in his approach and execution.

Pivetta’s breaking balls may offer one peek into what Fuld was describing about unintended consequences. It’s impossible to know exactly what to expect from any given tweak, even when pursuing what the data says makes the most sense to do in order to be better. 

There are other difficulties in continuing player development at the Major League level. Fuld refers to one as “threading the needle” — ultimately, understanding that “Player X can handle a little more than Player Y” when it comes to absorbing and processing all the data the team has about their game. Not everyone will be Justin Verlander upon arriving in Houston, and not everyone needs to be.

Fuld also detailed something that’s perhaps more important than understanding what a given player can handle, though. It’s critical to “create awareness for players that there are resources that can help them.” In other words, be present, but don’t be effusive. Build a relationship that starts with an open door and allows players to make the choice to seek what they can handle to enhance their game, instead of sliding it toward them from across a table in a meeting, with no context or plan.

Baseball rewards those who are confident and eats up those who are not. No one reaches the Major Leagues by accident, which makes it much easier for players to be risk-averse. But those who are willing to wade into unknown waters in the pursuit of progress, and be confident enough to navigate them? They can be stars.

WAR from FanGraphs. Pitch mix and movement data from Brooks Baseball. Feature photo Eric Hartline/USA Today Sports