The Sweeper

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mikey lowell of the sandbox
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Jun 27, 2006
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Breaking out from the April 30 game thread.

Judging by Bryce Miller's demonstration grip, the sweeper is a knuckle slider that sacrifices velocity for increased horizontal movement.

View: https://twitter.com/CoreyBrockMLB/status/1627757031590612992


Back in the days of DiceK, I used to call that pitch a slurve, but Youkilis insists that the slurve has more vertical drop, while the movement on the sweeper is almost entirely horizontal.
 

Just a bit outside

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Here is an article about hitting the sweeper. It has chart showing the difference in the speed and vertical and horizontal movement of the slider, sweeper, curve , and slurve. Sweeper is very close in horizontal movement to a slurve but close to a slider in vertical movement without gravity.
https://blogs.fangraphs.com/a-look-at-baseballs-best-horizontal-hitters/

Pitch Type Averages, 2023
Pitch Type Velocity Glove-Side Movement Vertical Movement
Sweeper 81.6 14.6 2.2
Slider 84.8 5.9 2.0
Curveball. 79.7 8.8 -8.9
Slurve 82.4 14.5 -3.1
 

TFisNEXT

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Jul 21, 2005
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Breaking out from the April 30 game thread.

Judging by Bryce Miller's demonstration grip, the sweeper is a knuckle slider that sacrifices velocity for increased horizontal movement.

View: https://twitter.com/CoreyBrockMLB/status/1627757031590612992


Back in the days of DiceK, I used to call that pitch a slurve, but Youkilis insists that the slurve has more vertical drop, while the movement on the sweeper is almost entirely horizontal.
Your last sentence got me thinking….did Byung Hyun Kim throw a sweeper from that lower arm angle? I remember his “slider” being very horizontal. And DiceK I recall having the a version of his slider that was like a “frisbee” ball as Jerry Remy used to describe it.
 

absintheofmalaise

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Out of curiosity I wanted to see how Sale's slider looked over the years to see if it could be classified as a sweeper. I picked 2016 and 2018 randomly in the Baseball Savant Illustrator. The horizontal movement should classify the pitch as a sweeper, but I'm not sure if the horizontal movement is because he releases it so far to his left because of his long arm or because of his grip. I'm not sure if he changers grips like the the post above for Miller shows. If anyone knows, please let us know.
The following shows the pitch location followed by his release point and then speed and spin rate. All from the catchers POV.
Baseball Savant doesn't have sweeper in the pitch type to choose from for Sale, but they do for Logan Allen and they know a hell of lot more than I do about this. They don't have a slider for Allen.
Just wanted to see what others thought.

2016
6421364214
2018
6421664217
 

Yo La Tengo

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Nov 21, 2005
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I feel like the sweeper is a slider thrown slightly slower to get more horizontal break? It looks like it comes out of the pitchers hand with arm extended and the hand on the side of the ball, the same as a slider. I'd be interested to see how far back in the hand pitchers are holding the sweeper- usually the "tighter" the grip, the slower the slider and the loopier the break.

I've always understood that curveballs break down and are thrown with the fingers on the front of the ball, with the arm bent at the elbow. In contrast, sliders are thrown with the fingers on the side of the ball, full extension, and have more of a flat break (horizontal), and slurves (a combo of the two) are to be avoided (righty v righty and left v lefty), since the break lines up with the swing angle of the batter.

But, I'm reading that a slider has "gyro" spin while a sweeper relies on "seam-shifted wake" and I'd love some explanation on the difference of those two things.


EDIT- for example, this looks like a slow slider to me:

View: https://twitter.com/PitchingNinja/status/1652737113501184000
 
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Yo La Tengo

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Nov 21, 2005
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Some thoughts from Dave Bush:

"It's really not new at all,'' chuckled pitching coach Dave Bush. "We just have a new name for it. By pitch shape, it's not new, but it's more prevalent now. We see that a lot with pitches in the game. When somebody does something that's successful or seems new or is more common than it used to be, it gets a lot more attention and with things that are successful, oftentimes we chase what works.
. . .
"It used to be that, unless you were really paying close attention, you didn't know that sliders look a little different than they used to be. But now we have information to everyone. It's pretty detailed and pretty accurate. So the awareness for things that are happening is much more than it used to be and that makes things easier to talk about and more common.''

Bush describes the pitch as "a bigger breaking slider than the more traditional smaller ones. The name sounds kinda cool. I think people like saying 'sweeper.' It sounds fun and it looks cool. You see a big sideways breaking ball that gets swings and misses. But I don't really care what we call stuff. If it's effective, then we're going to use it.''
 

StupendousMan

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I've always understood that curveballs break down and are thrown with the fingers on the front of the ball, with the arm bent at the elbow. In contrast, sliders are thrown with the fingers on the side of the ball, full extension, and have more of a flat break (horizontal), and slurves (a combo of the two) are to be avoided (righty v righty and left v lefty), since the break lines up with the swing angle of the batter.

But, I'm reading that a slider has "gyro" spin while a sweeper relies on "seam-shifted wake" and I'd love some explanation on the difference of those two things.
I'm afraid that I don't have time for a very long answer here, but one way to characterize the difference is in the direction of the ball's spin. The direction of the break is given by the cross-product of the spin axis and the ball's velocity toward the plate. You can find some diagrams that will explain this at

http://spiff.rit.edu/richmond/baseball/traj_may2011/traj.html
http://spiff.rit.edu/richmond/baseball/pitch_series/arm_angle/arm_angle.html

A "typical" slider has a spin axis which is mostly horizontal, with a slight tilt; see the diagram about halfway through this article on the slider. The "horizontal" portion of the spin causes the ball to break up, while the "vertical" portion of the spin causes the ball to break horizontally. Thus, an ordinary slider has only a small amount of horizontal motion. If one wishes to increase the horizontal break, one must release the ball so that its spin axis is oriented closer to vertical. The maximum possible horizontal break would occur if the ball were rotating around a perfectly vertical axis: use a pen to mark "North Pole" at the top of the ball, and throw it so that the dot remains at the top of the ball all the way to the plate.

So pitchers who throw a "sweeper" must be using their fingers and wrist motion to give the ball a) a rapid spin which b) has a (mostly) vertical spin axis. Imagine yourself floating above the ball and looking down at it as it hurtles toward the plate. If the ball is spinning clockwise (as seen from above), then it will break towards third base; if the ball is spinning counterclockwise, it will break toward first base.

As for the "gyro" vs. "seam-shifted wake", I can only speculate. A true gyro ball has a spin axis which points straight at home plate; the little dot on the ball marked "North Pole" would always point straight at the batter. Such a pitch would have ZERO break: it would follow exactly the same path as a ball thrown without any spin at all. Ordinary sliders are slightly different: their spin axis points away from home plate by a medium-size angle, perhaps 30 to 50 degrees. But a batter with excellent vision might notice that the red color of the seams is concentrated in one location -- that marks the location of the spin axis. For a slider with a small break, the red dot points closer to the batter, and is probably easier to notice. Perhaps, then, a "gyro spin slider" is one that doesn't break very far. A "sweeper" with maximum horizontal break would place the red dot at the very top (or bottom) of the ball, invisible to the batter's view as it flies toward him.

I have no idea how one would hold a ball or snap one's wrist in order to create a perfectly vertical spin axis. Perhaps some of our active pitchers or pitching coaches can enlighten us.
 

Yo La Tengo

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Nov 21, 2005
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I had a minute to dig around and found this really helpful write-up addressing seam shifted wake, which appears to not be primarily created by a particular spin axis but by airflow patterns created by seam positioning. My overly simplified summary is the sweeper is a slider with the seams held in such a way as to create disruptive airflow around the ball that results in a larger break:


"The action on this pitch is much better than the traditional slider. The only downside is velocity, with the Sweeper going about 3.2 MPH slower on average than the traditional slider in 2021. Yet, speed was never the point of an effective slider - last year's data suggests the Sweeper spins 125 more RPMs than the regular version of this pitch. This causes more break, with the regular slider breaking 7 inches horizontally and the Sweeper breaking 15 inches (a roughly 114% improvement). But while spin is important in some cases, the deadliness of this pitch is not entirely caused by the high spin rate. It is owed to a newer scientific concept that is breaking the way physicists think of pitching.

Introducing Seam-Shifted Wake - the cause of this absurd pitch. Originally discovered by Alan Nathan using Pitch F/X Data (the private version of MLB data before Statcast), he found that the degree of late movement that certain pitches have are not owed to the regular concepts of pitching. To properly explain this, I will attempt to boil down the science behind the concept, as I believe knowing that is incredibly important in understanding how this pitch is physically possible. When a regular pitch is thrown, it is usually subject to a “Magnus” effect - a pitch moves based on how the ball is being held and the slip of the fingers behind the spin. Regular pitches are under the influence of this effect, spinning in the same manner from the pitcher's hand to the plate, moving as when the ball left the hand. The Sweeper, and other pitches that are prone to seam-shifted wake, are not limited to this Magnus. Instead, they experience a state of Non-Magnus. When under this state, a pitch can gain free movement, curving and moving in ways that didn’t come originally from the hand grip. In a sense, the ball appears to be moving on its own. But it’s not - it’s experiencing a heavy dose of Seam-Shifted Wake."

https://www.thedrummeyangle.com/post/pitching-s-newest-fever-seam-shifted-wake-and-the-sweeper

This video is from 3 years ago- really fascinating:

View: https://www.youtube.com/watch?v=7KwKM0SjLng&t=334s
 
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ElsyDuffy

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May 4, 2023
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I had a minute to dig around and found this really helpful write-up addressing seam shifted wake, which appears to not be primarily created by a particular spin axis but by airflow patterns created by seam positioning. My overly simplified summary is the sweeper is a slider with the seams held in such a way as to create disruptive airflow around the ball that results in a larger break:


"The action on this pitch is much better than the traditional slider. The only downside is velocity, with the Sweeper going about 3.2 MPH slower on average than the traditional slider in 2021. Yet, speed was never the point of an effective slider - last year's data suggests the Sweeper spins 125 more RPMs than the regular version of this pitch. This causes more break, with the regular slider breaking 7 inches horizontally and the Sweeper breaking 15 inches (a roughly 114% improvement). But while spin is important in some cases, the deadliness of this pitch is not entirely caused by the high spin rate. It is owed to a newer scientific concept that is breaking the way physicists think of pitching.

Introducing Seam-Shifted Wake - the cause of this absurd pitch. Originally discovered by Alan Nathan using Pitch F/X Data (the private version of MLB data before Statcast), he found that the degree of late movement that certain pitches have are not owed to the regular concepts of pitching. To properly explain this, I will attempt to boil down the science behind the concept, as I believe knowing that is incredibly important in understanding how this pitch is physically possible. When a regular pitch is thrown, it is usually subject to a “Magnus” effect - a pitch moves based on how the ball is being held and the slip of the fingers behind the spin. Regular pitches are under the influence of this effect, spinning in the same manner from the pitcher's hand to the plate, moving as when the ball left the hand. The Sweeper, and other pitches that are prone to seam-shifted wake, are not limited to this Magnus. Instead, they experience a state of Non-Magnus. When under this state, a pitch can gain free movement, curving and moving in ways that didn’t come originally from the hand grip. In a sense, the ball appears to be moving on its own. But it’s not - it’s experiencing a heavy dose of Seam-Shifted Wake."

https://www.thedrummeyangle.com/post/pitching-s-newest-fever-seam-shifted-wake-and-the-sweeper

This video is from 3 years ago- really fascinating:

View: https://www.youtube.com/watch?v=7KwKM0SjLng&t=334s
Thank you for the video.