Looking Knuckleball, Part 1
The Last Surviving Knuckleballer
A few days ago I posted about what to expect from Daisuke. Next, I'd like to take a more in-depth look at Tim Wakefield, the last surviving knuckleballer (I know, R.A. Dickey pitches for the Mariners, and Haeger is still floating around the White Sox organization, and our very own Charlie Zink is dominating the minors, but doesn't it sound more impressive to be the last of one's kind?).
Tim Wakefield, the last surviving Knuckleballer.
The Repertoire
Everyone knows Wakefield throws the Knuckler - he also throws a fastball (at a blazing 73 mph) and one of the slowest curves still thrown (57-59 mph). Depending on the count, your chances of seeing a curve and fastball vary quite a bit: if you manage to get ahead of Wakefield, you're likely to see the fastball; if you manage to fall behind, you may see the curve. This isn't rocket science: the fastball is thrown when Tim needs a strike, and the curve is thrown when Tim has the hitter set up and expecting knuckleball, only to see the slow hammer dive sharply into the strikezone. But, for the most part, Tim isn't up there dazzling with excellent fastball command or flashing his knee-buckling bender. He's up there to do one thing, and do one thing well: throw a 66-68mph butterfly, pitch after pitch.
Breaking Down a Single AB
Before looking at a large plot of dozens of knuckleballs it helps to acquaint oneself with the actual movement on the pitch. Most people watch it on TV and laugh when guys swing and miss because it doesn't look that hard to hit. The color commentator, especially if he's an ex-player, is trying to convince you (probably with little success) that it really is hard to hit a knuckleball, all while Wakefield appears to effortlessly get up there and deliver the same 68mph junk ball. So, rather than focus on the aggregate (that will be Part 2), we're going to focus on a single At-Bat - a strikeout of Jack Cust on 8/1/08.
To try to give you a sense of exactly what the ball is doing, here's an overhead view during a single at-bat during which Wakefield threw only Knuckleballs:
That's right. All four of those pitches (resulting in a strikeout) were knuckleballs, even though one of them has a really heavy outside tailing movement, two curve to the right, and one sails far inside (Cust is a LHH).
The Psychology of Hitting the Knuckleball
Let's take a minute to break down the psychology of actually hitting the Knuckleball. Remember that for the most part, although pitchers try to be deceptive and generally throw things that are tough for hitters to tell apart, their pitches, if discriminable, follow relatively predictable trajectories. If you could tell with 100% fidelity that a four-seam fastball was a four-seam fastball and a curve was a curve, you would have a pretty good idea of when and where to swing the bat. Second, most hitters get up there and "guess". They get in a particular count, have received extensive scouting information about a pitcher, have seen a number of pitches, and sometimes have good information about what they're likely to see (sometimes not, if the batter is badly fooled).
Right away, one of the large advantages of throwing a knuckleball is that neither of these strategies work. For the most part, except in rare situations, hitters know they're going to get the knuckleball, so "guessing right" doesn't help. Second, when they first recognize the pitch as a knuckleball, this gives them no particular advantage in hitting it, because they have no good information about where the thing is going to go.
Another way of saying it: hitting the knuckleball is hard because it's random. Suppose your swing needs to start about .25 seconds before the pitch reaches the plate, close to the ~225-235ms time estimated by Robert Adair in The Physics of Baseball (though this probably needs to be updated). Even though it might look relatively slow on TV, the average time-to-plate of a Tim Wakefield Knuckler is about 500 ms. That means that all the information you get about a relatively random trajectory is in the first half of it's flight to the plate, and you've just got to make your best educated guess at what the second half is going to be.
Let's take a look at that information. I've broken down the knucklers from this at-bat into two groups: the last 250ms of each pitch's trajectory, which we know that the hitter cannot see before deciding to swing, and the the time before that, which we approximate the hitter can see. For example, here is a look at those same knuckleballs in a similar format:
This is straight down on top of the pitch trajectory, just like the plot a few paragraphs ago. Okay, so we might be able to connect those trajectories to their eventual locations, but especially with the two on the left (both of which were swinging strikes), we've got very little information to work with. Remember, up to this point, the hitter has no idea how much more each of those pitches is going to move. Here's how much they do move after the hitter's last look at the pitch before deciding to swing:
From this view alone, we can see that a large majority of the knuckleball's movement actually occurs AFTER the hitter has decided to swing (or not) at the pitch. Essentially, if you're swinging at a knuckleball with a lot of movement, you're really just making a guess as to where it's going to end up.
The same is true of vertical movement. Here's the "before" shot of Knuckleballs from a side view:
Which one of these will eventually be the highest ball? It might not be the one you think:
These knucklers actually have fairly uniform movement in the vertical axis, although one sails up. Still, compare the two plots and you see that by far the most movement occurs after the hitter's decision point.
But still, you might think: "this really isn't that hard." Maybe you're good at matching trajectories and it isn't all that difficult to tell these ones apart. How does Jack Cust fail so badly at this task?
Remember that Jack is looking at the pitch from the Batter's Box, and so part of his ability to see trajectory information is further obscured by his angle relative to the release. Even though Wakefield is a RHP and Cust is LHH, there's still a relative distortion on the trajectory information available to the hitter compared to looking at the pitch straight along one of the axes of movement.
And the post-perceptual trajectory of these pitches:
I hope I've convinced you that through looking at only a single at-bat, it's really not so easy to hit the Knuckleball. This is mainly due to two factors: the fact that the movement of the knuckleball is highly random, and the fact that most of this movement occurs after the batter has made his decision to swing. In Part 2, we'll look at the aggregate movement of the Knuckleball. For a preview, here are the aggregate plots from the 8/1 start:
Notes
You can comb through all the data from Tim Wakefield's start on 8/1 by using my PitchFX Tool. Click here to go directly to this game's data.
Dan Fox wrote an article about aggregate data on the Knuckleball for an issue of Baseball Prospectus.
A few days ago I posted about what to expect from Daisuke. Next, I'd like to take a more in-depth look at Tim Wakefield, the last surviving knuckleballer (I know, R.A. Dickey pitches for the Mariners, and Haeger is still floating around the White Sox organization, and our very own Charlie Zink is dominating the minors, but doesn't it sound more impressive to be the last of one's kind?).
Tim Wakefield, the last surviving Knuckleballer.
The Repertoire
Everyone knows Wakefield throws the Knuckler - he also throws a fastball (at a blazing 73 mph) and one of the slowest curves still thrown (57-59 mph). Depending on the count, your chances of seeing a curve and fastball vary quite a bit: if you manage to get ahead of Wakefield, you're likely to see the fastball; if you manage to fall behind, you may see the curve. This isn't rocket science: the fastball is thrown when Tim needs a strike, and the curve is thrown when Tim has the hitter set up and expecting knuckleball, only to see the slow hammer dive sharply into the strikezone. But, for the most part, Tim isn't up there dazzling with excellent fastball command or flashing his knee-buckling bender. He's up there to do one thing, and do one thing well: throw a 66-68mph butterfly, pitch after pitch.
Breaking Down a Single AB
Before looking at a large plot of dozens of knuckleballs it helps to acquaint oneself with the actual movement on the pitch. Most people watch it on TV and laugh when guys swing and miss because it doesn't look that hard to hit. The color commentator, especially if he's an ex-player, is trying to convince you (probably with little success) that it really is hard to hit a knuckleball, all while Wakefield appears to effortlessly get up there and deliver the same 68mph junk ball. So, rather than focus on the aggregate (that will be Part 2), we're going to focus on a single At-Bat - a strikeout of Jack Cust on 8/1/08.
To try to give you a sense of exactly what the ball is doing, here's an overhead view during a single at-bat during which Wakefield threw only Knuckleballs:
That's right. All four of those pitches (resulting in a strikeout) were knuckleballs, even though one of them has a really heavy outside tailing movement, two curve to the right, and one sails far inside (Cust is a LHH).
The Psychology of Hitting the Knuckleball
Let's take a minute to break down the psychology of actually hitting the Knuckleball. Remember that for the most part, although pitchers try to be deceptive and generally throw things that are tough for hitters to tell apart, their pitches, if discriminable, follow relatively predictable trajectories. If you could tell with 100% fidelity that a four-seam fastball was a four-seam fastball and a curve was a curve, you would have a pretty good idea of when and where to swing the bat. Second, most hitters get up there and "guess". They get in a particular count, have received extensive scouting information about a pitcher, have seen a number of pitches, and sometimes have good information about what they're likely to see (sometimes not, if the batter is badly fooled).
Right away, one of the large advantages of throwing a knuckleball is that neither of these strategies work. For the most part, except in rare situations, hitters know they're going to get the knuckleball, so "guessing right" doesn't help. Second, when they first recognize the pitch as a knuckleball, this gives them no particular advantage in hitting it, because they have no good information about where the thing is going to go.
Another way of saying it: hitting the knuckleball is hard because it's random. Suppose your swing needs to start about .25 seconds before the pitch reaches the plate, close to the ~225-235ms time estimated by Robert Adair in The Physics of Baseball (though this probably needs to be updated). Even though it might look relatively slow on TV, the average time-to-plate of a Tim Wakefield Knuckler is about 500 ms. That means that all the information you get about a relatively random trajectory is in the first half of it's flight to the plate, and you've just got to make your best educated guess at what the second half is going to be.
Let's take a look at that information. I've broken down the knucklers from this at-bat into two groups: the last 250ms of each pitch's trajectory, which we know that the hitter cannot see before deciding to swing, and the the time before that, which we approximate the hitter can see. For example, here is a look at those same knuckleballs in a similar format:
This is straight down on top of the pitch trajectory, just like the plot a few paragraphs ago. Okay, so we might be able to connect those trajectories to their eventual locations, but especially with the two on the left (both of which were swinging strikes), we've got very little information to work with. Remember, up to this point, the hitter has no idea how much more each of those pitches is going to move. Here's how much they do move after the hitter's last look at the pitch before deciding to swing:
From this view alone, we can see that a large majority of the knuckleball's movement actually occurs AFTER the hitter has decided to swing (or not) at the pitch. Essentially, if you're swinging at a knuckleball with a lot of movement, you're really just making a guess as to where it's going to end up.
The same is true of vertical movement. Here's the "before" shot of Knuckleballs from a side view:
Which one of these will eventually be the highest ball? It might not be the one you think:
These knucklers actually have fairly uniform movement in the vertical axis, although one sails up. Still, compare the two plots and you see that by far the most movement occurs after the hitter's decision point.
But still, you might think: "this really isn't that hard." Maybe you're good at matching trajectories and it isn't all that difficult to tell these ones apart. How does Jack Cust fail so badly at this task?
Remember that Jack is looking at the pitch from the Batter's Box, and so part of his ability to see trajectory information is further obscured by his angle relative to the release. Even though Wakefield is a RHP and Cust is LHH, there's still a relative distortion on the trajectory information available to the hitter compared to looking at the pitch straight along one of the axes of movement.
And the post-perceptual trajectory of these pitches:
I hope I've convinced you that through looking at only a single at-bat, it's really not so easy to hit the Knuckleball. This is mainly due to two factors: the fact that the movement of the knuckleball is highly random, and the fact that most of this movement occurs after the batter has made his decision to swing. In Part 2, we'll look at the aggregate movement of the Knuckleball. For a preview, here are the aggregate plots from the 8/1 start:
Notes
You can comb through all the data from Tim Wakefield's start on 8/1 by using my PitchFX Tool. Click here to go directly to this game's data.
Dan Fox wrote an article about aggregate data on the Knuckleball for an issue of Baseball Prospectus.
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