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Why Do Sweepers Cause So Many Popups?

© Jayne Kamin-Oncea-USA TODAY Sports

We’re still in a relatively new era of pitch design. Just this past year, we saw several successful pitchers embrace a sweeping breaking ball. Last month, Justin Choi wrote about one of those pitchers, Julio Urías, and noted that his new sweeper generates a great number of popups and lift. It’s not just Urías; in general, sweepers have a tendency to generate balls hit in the air at a rather skewed clip:

It’s strange behavior not just for a non-fastball, but for a breaking pitch especially; as you can see, sweepers have nearly double the popup rate of their fellow breaking balls:

Batted Ball Distribution: Breaking Pitches, 2021
Non-Sweeper 45.2% 23.7% 24.8% 6.4%
Sweeper 36.1% 22.3% 30.7% 10.9%
SOURCE: Baseball Savant

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The Best Fit for Any Version of Carlos Rodón

Kamil Krzaczynski-USA TODAY Sports

As one of the few remaining free-agent pitchers, there will be a time (hopefully) soon enough when Carlos Rodón is a hot commodity. A pitcher coming off a 4.9 WAR season usually doesn’t have serious contract questions attached to them, but that’s the case for Rodón, who amassed that WAR total in only 132.2 innings and was given significant rest between starts, as his velocity dipped significantly over the course of the year. The end result is that he didn’t receive a qualifying offer from the White Sox and remained unsigned as the lockout began.

Rodón’s injury history combined with the in-season fatigue is alarming on its own, but a pitcher who can put together a 5-win season in under 200 innings deserves a fair assessment. How likely is it that those fatigue issues occur again, and if they do, what team is best suited to handle a mixed starter/reliever workload?

We’ll start with assessing the fatigue issues. As noted, Rodón threw 132.2 innings in 2021 — rather remarkable, considering he had only thrown 42.1 innings in ’19 and ’20 combined. Innings jumps that large are understandably scary, but every pitcher experienced that after the 2020 season; Rodon’s was the 24th largest year-to-year increase from that season to last year. That is something, but there was a significant lack of workload for Rodón in 2019 as well. Where does he rank in terms of innings jumps from 2019 and ’20 combined to 2021?

2021 Workload Increasers
Name 2021 IP 2019-20 IP Increase
Shohei Ohtani 130.1 1.2 128.9
Alek Manoah 129.2 17.0 112.2
Lance McCullers Jr. 166.1 55.0 111.1
Jameson Taillon 147.1 37.1 110.0
Triston McKenzie 141.1 33.1 108.0
Jordan Montgomery 157.1 51.2 105.9
Taijuan Walker 159.0 54.1 104.9
Peter Solomon 111.2 7.2 104.0
Carlos Rodón 132.2 41.4 90.8
Chris Flexen 179.2 91.4 87.8
Tyler Anderson 167.0 79.4 87.6

Many of the pitchers here have suffered significant injuries before and once again ran into injury troubles this past season. Regardless, the jump for Rodón was not unprecedented; what’s maybe more concerning is the velocity drop in-season.

Rodón’s velo saw a more characteristic switch after his last start of seven-plus innings on July 18. Before then, there was a clearer build-up from innings 1–3 to innings 4–6; after, the relationship breaks. That start on the 18th was seemingly max effort the whole time, with the highest early-inning velocity he’d shown all year. There’s nothing that we can reasonably assume about the nature of his shoulder fatigue, whether it’s this one start that caused trouble or having hit a wall in general, but his season decline began there. He had built up to 89.2 innings before that July 18 start; everything after has the caveat of him either throwing through noticeable injury, receiving extended periods of rest, or spending time on the IL.

If we take those 89.2 innings as a benchmark of the healthy Rodón, we can look at other year-to-year workload increases to get a sense of what may be reasonable.

For those that do throw somewhere in the range of 90 innings, jumps in the range of 30–40 innings are within reason, although many of those who fall into that 80–90 range are midseason call-ups. In the 130-inning range, best-case jumps top out at 20 or so innings. Barring injury and without much else information to bake in, we would expect Rodón in 2022 to fall somewhere between 110 and 150 innings.
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Thinking About Horizontal Approach Angle

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 »

White Sox Maintain Insurance Policy, Re-sign Leury García

In news that was buried under the pre-lockout transaction rush, the White Sox brought back 30-year-old utility man Leury García on a three-year deal for $16.5 million. Despite a season slash line of .267/.335/.376, he still put up 2.0 WAR in 126 games, a testament to his defensive prowess.

It’s the bat that has been the issue, as you can see in his career 80 wRC+, though his 98 wRC+ in 2021 was a significant step up. The lack of power is the largest hole in García’s offense, or at least the clearest area for improvement. There is some measurable power, with a max exit velocity of 109.6 mph that is above league average, but it’s largely undone by a 55% ground-ball rate. He lags behind those with similar exit velocity in barrel rate, too.

Deficiencies with the bat don’t matter so much with García, though, as he is through and through a utility man, and while many players end up playing a bevy of positions, he is firmly in the Chris Taylor tier. Both were the only two players to play at least 60 innings at six different positions in 2021 — the only two with at least 30, in fact.
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José Urquidy’s Offspeed Makeover

José Urquidy delivered a relative gem in Game 2 of the World Series, punching out seven and giving up two runs with no walks in five innings. Included in that was a big bump in velocity across the board: Urquidy’s fastball gained 0.6 mph from its regular-season average (93.1 versus 92.5); his changeup spiked nearly two miles per hour (86.2 versus 84.4); and his slider saw the largest increase, from 79.3 mph to 81.7. Dialing up the velocity to this extent can effectively create new pitches, and with that an element of unpredictability, particularly when it comes to a pitch’s movement. That can be a plus in the postseason, but what about the flip side; could that extra velocity and movement make things worse?

On the surface, Urquidy throwing his hardest fastballs of the year in his most important start can’t be a bad thing, assuming it doesn’t compromise his command. Can he so precisely regulate the velocity of his offspeed offerings? Amazingly, we might be seeing the reverse from Urquidy, who seems to be throwing the offspeed stuff harder but holding back on the fastball.

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Kyle Tucker Is Hitting Seventh and That’s Fine

Kyle Tucker has evolved into the elite hitter the Astros and scouts believed he could be. The outfielder, who graduated from prospect status in 2019 with a 60 Future Value grade and ranked 10th on our top 100 that preseason, is slashing a robust .290/.355/.548 in 548 plate appearances, good for a 144 wRC+ — tops on the team — and 4.5 WAR. David Adler of recently wrote about how good Tucker has been this season, but I want to focus on how he’s being used, and whether the Astros are giving away an advantage with where they’re hitting him.

The Astros are dealing with injuries, as they have all season, with Michael Brantley the latest regular to land on the injured list. As such, the last game in which they had all of their starters in the lineup was on September 11, and it looked like this:

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Attrition is Catching Up to Oakland’s Bullpen and Playoff Odds

The A’s are nearly on the outside looking in. With about two weeks left in the season, there’s still room for a pair of AL East cold streaks to swing things around, but the odds of Oakland reclaiming a Wild Card spot and making the playoffs for a fourth straight year are slim.

Those odds cratered in the past month; some of that collapse is more succinctly summarized here. Any four-year playoff run is impressive, but the Oakland teams of the past three years, including two 97-win squads, have been devoid of the quality of starting pitching that their record would suggest. This season will be the first the A’s have had in that stretch with any starting pitcher compiling 3-plus WAR, let alone three of them. But while the gains in starting pitching are most certainly helpful, there has been a considerable dip in the quality of Oakland’s relievers.

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A Cursory Investigation of the Backup Slider

I wish I could come to you with news about the mass adoption of backup sliders from pitchers across the league. I also wish I could come to you with a shining example of even one player who has perfected the art of the effective mistake. There is no apparent analytical case that comes to mind; it’s largely just a fascination to me — the best hitters in the world swinging through the worst offering a pitcher could imagine throwing. Here’s an example:

Matt Wisler is the perfect guy to have here — someone who throws nothing but sliders making the biggest kind of slider mistake! And yet there are times when it just works. What I want to try to answer is what makes these mistake sliders click without diving into the rabbit hole of pitch sequencing. Are there particular characteristics of movement and velocity that make for better backup sliders?

First, we have to set guidelines on what a backup slider is. You know it when you see it, but it is more broadly defined as something that “hangs” when thrown to a batter of the same handedness. Sliders behave differently depending on whether they’re thrown inside or out, as shown by Eno Sarris on this site a few years back; those away gain almost half a foot of horizontal movement compared to ones thrown inside! Sliders need height to be considered mistakes, but the distinctions in horizontal movement are too vast for an outside-and-up slider to be as bad a mistake as one up but inside. For our purposes, let’s say that a backup slider is anything in the upper third of the strike zone, middle-to-in, in a same handedness matchup. Read the rest of this entry »

Attempting to Predict Fernando Tatis Jr.’s Outfield Defense

Fernando Tatis Jr. is now an outfielder for the San Diego Padres. Despite his recent stint on the injured list — his third of the season, and his second related to his shoulder — he might end up collecting the NL MVP provided he can stay productive and healthy, all while moving away from the only position he’s played in professional baseball. In his return to action on Sunday, he raised his wRC+ to 172 and got his first playing time in right field. There wasn’t much to be gleaned from the four balls hit his way, however, leaving us to wonder how well he’ll handle the position going forward. Mike Petriello at has covered the unprecedented nature of this move, but I want to take a look at what we can actually expect from Tatis defensively. I’m not the first to consider the question. Last week, Michael Ajeto highlighted Tatis’ defensive ability in an article for Baseball Prospectus and delved into the analytical precedent for shortstops who have recently made the conversion to the outfield. Today, I’ll look at what we might predict about Tatis’ outfield defense given some of the other data we have about his speed.

But let’s set the stage. The biggest flaw in Tatis’ game since his debut has been his defense. After a 2019 characterized by 18 errors and poor defensive metrics, he seemed right the ship last season. But his defense has since regressed, and while his -4.3 Def runs at shortstop this year hasn’t made him unplayable at the position, it’s certainly not ideal. Still, this move wasn’t necessitated by his play at short, but rather by Tatis’ recurrent shoulder problems and the Padres’ stated desire to shield him from further injury, though as Ajeto noted in his piece, whether that will actually work is an open question.

That’s how we ended up with Tatis in the outfield. Before getting too far ahead of ourselves, however, it’s important to know how his numbers at short are derived. His penchant for throwing errors is well documented and they do serve to drop his DRS, UZR, and Outs Above Average (OAA) considerably. We can peek at the component parts of UZR to separate the errors from Tatis’ range, but we aren’t even close to a three-year sample and thinking about UZR sample size is a Pandora’s Box that should be kept closed for today, anyhow. For our purposes, we’re not going to pay much attention to throwing errors or even Tatis’ range on grounders as a shortstop. The baseline we care about is how well he can play right field and quick twitch and speed are the parts of the shortstop skillset that seem mostly likely to translate to the outfield grass. Read the rest of this entry »

Chris Bassitt Has Gone From Good to Great — And Better Might Be Possible

The A’s are in the midst of another playoff hunt as they look to make their fourth postseason in a row, but this looks to be the first year in the run where a reliever doesn’t lead the pitching staff in WAR. Up there with Sean Manaea (2.9 WAR, 127 IP), Chris Bassitt (2.4 WAR, 137 IP) has taken a big step forward in his development, working a career best 19% K-BB%. Manaea’s success can be attributed to an across-the-board velocity spike (roughly 2 mph) that’s made an already great arsenal exceptional. Bassitt’s breakout is less clear and warrants some investigation.

Before I get into usage, I should note that his four-seam fastball velocity is a pedestrian 93.4 mph (league average is 93.7), and the shape on the four-seamer, sinker, and cutter are also average relative to the league.

For clarification on the sinker and cutter, vertical movement values greater than zero mean more drop than average. The four-seamer is rather poor when it comes to having the ride we associate with success in today’s game. The sinker, while it does well by horizontal movement, is still below average by vertical movement. And while the cutter shows great drop, there is a lack of cut or horizontal movement.

Despite being the only pitch with good vertical movement, though, it’s the cutter that has been lagging.

Chris Bassitt Fastball Results
Pitch Type % Usage BA SLG SwStr%
Sinker 38.1% 0.256 0.390 5.3%
Four-seamer 18.3% 0.180 0.279 14.3%
Cutter 17.9% 0.360 0.587 9.2%

I bring all this up because these are the pitches that Bassitt overwhelmingly relies upon, and it’s a unique combo.

Combined Fastball (FF, SI, FC) Usage Leaders
Name Combined FB%
Lance Lynn 92.5
Tyler Anderson 75.1
Chris Bassitt 73.4
Yusei Kikuchi 70.4
Walker Buehler 69.3
Chris Flexen 68.2
SOURCE: Baseball Savant
Among Qualified Starters

It’s an extreme approach, mashing together a combination of three average pitches by movement to the tune of a 3.51 FIP. There is no extension magic, but there is maybe some vertical approach angle ability at play.

There are far more robust calculations for vertical approach angle that are unavailable to me, but we can leverage some quick back of the envelope geometry to work with a loose version of our own. Just using release height, pitch height, and release extension, Bassitt is above average in keeping a flat approach angle that can paper over the lack of vertical movement. (“Above average” means that he does well to locate up in the zone but also releases from a lower height.)

Better than trying to justify my choice of simple geometry, how about I just show you where Bassitt stands by release and average location?


There’s great height on the four-seamer, but what’s arguably as important is how low Bassitt’s release is for a player of his height. One way to hack a non-rising four-seamer is to release it as low as possible but throw it high in the strike zone to recreate the same plane where a hitter feels like he has to adjust his hands to get his barrel where it needs to be. Bassitt does just this; he’s 6’5”, but his release is nearly a foot lower at 5.5 feet. There’s a flatness to the four-seamer that helps it play up in the zone, and the sinker still has enough raw movement to be effective as well.

Tunneling pitches and locating is great, but every pitcher wants to be more unpredictable to a hitter. Bassitt is in a high tier when it comes to combined fastball usage, but there’s a difference that should be noted on a per-plate appearance basis. What does that look like for the hitter? How often should someone step in against Bassitt and expect only fastballs?

Fastball Only PA Leaders
Name % PAs FB only
Lance Lynn 77.3%
Tyler Anderson 45%
Matt Peacock 45%
Josh Fleming 39.9%
Wade Miley 39.7%
Riley Smith 39.6%
Chris Bassitt 39.1%
Jon Lester 38.9%
Michael Wacha 38.8%
Eric Lauer 37.8%
SOURCE: Baseball Savant
Min 250 Batters Faced

For a plate appearance against Bassitt, more often than not, a batter will have to expect an offspeed pitch at some point. The changeup, slider, and curve are featured less than 10% of the time, but the changeup is the only of those pitches that can be thrown with more regularity because it doesn’t have a huge velocity gap (15-plus mph) with the fastball like the curve and slider do. The curve is so loopy and slow it’s almost a kind of shock pitch to steal a strike, and while the slider is fine by movement, it may be too slow to throw with regularity to lefties.

What Bassitt does is overcome his inherent fastball movement, particularly the lack of rise that is so desired for four-seamers in today’s game. Not only that, but he’s also found a mix that allows him to throw what he can command well while still having enough in his arsenal to keep batters thinking about the offspeed coming their way. Performing as well as he is right now with this much fastball usage opens up the door for a more refined slider and/or cutter to take a larger role down the road.

Bassitt can follow Lynn as a roadmap, but with the cutter as poorly performing as it is and the slider platoon dependent, there’s room for him to grow. He has found great success not having to throw a slider more often or a better performing cutter, but there’s a possible next level if he felt the need to become more unpredictable. Despite somewhat below average raw stuff, he has excelled — and there are still steps he can take to get even better.