The grip on the ball has a lot to do with it. The reason that a 4-seam FB doesn't drop in velocity as fast as a 2-seam FB is that that seams trap a boundary layer of air against the ball. That reduces the amount of drag. If an OF instinctively rotates the ball to a 4-seam grip before letting it fly, it will reach it's target quicker and be less likely to tail off line. It's just a good habit to train the guys in at a young age.
Some older guns used to get the pitch speed out of hand while others picked it up after the ball had traveled about 20 feet.
The newer style guns are much more accurate.
obtw: The faster the spin, the less drag you get. So it's a factor of both grip on the ball and how you release it, not just arm speed, but both of those things can be taught to an OF. It's not rocket science...... it relates more to the properties of rotating bodies in a fluid medium. (ok, ok ... maybe it is like rocket science)....
HiHardHeat - Well done!
Do you have a resume you can send me. We may be hiring soon at NASA.
Do you have a resume you can send me. We may be hiring soon at NASA.
quote:Originally posted by Midlo Dad:
Is there no one at Fox who took science in high school?
Clearly, they're using one of these:
I don't think it is a bunch of hooey----I have no idea if their numbers are correct but I have to believe that the speed at the plate has to be less than from the hand
I'd have to go with Midlo on this one, it's a useless stat. It has nothing to do with reaction time, how the hitter reacts to the pitch, etc.
But I do think they should let the DH hit with aluminum.
But I do think they should let the DH hit with aluminum.
Actually it is fairly meaningful as the speed at which the ball approaches the plate is generally more important than the reaction time. A ball that doesn't slow down as much as expected or slows down more than expected throws off a hitter's timing and throwing off timing is much more important than reaction time.
My point is this.
Draw yourself a diagram from the side view, where the gun is up in the stands behind home plate. Plot the pitcher's release point, the catcher's mitt location, the path of the ball and the angle from the gun to the ball at various points along the ball's path.
Remember that due to g the ball's path will be parabolic, not linear. So, as the ball reaches home the angle of the gun vis a vis the velocity vector of the ball's instaneous direction will be greater.
The gun will read only the sine of the angle, not the full velocity vector.
So yes, you will get fall off in your MPH readings as the ball approaches home, but no, the ball is not actually losing speed at that rapid rate. Maybe a little, but not that much.
A 2-seamer will read a greater drop not because of air cushion effect, because that is negligible. The issue is that if some of the ball's forward momentum is transferred to sideways or downward movement, again you will get a resulting reduction in the forward vector. For curves the effect will be even more pronounced.
Draw yourself a diagram from the side view, where the gun is up in the stands behind home plate. Plot the pitcher's release point, the catcher's mitt location, the path of the ball and the angle from the gun to the ball at various points along the ball's path.
Remember that due to g the ball's path will be parabolic, not linear. So, as the ball reaches home the angle of the gun vis a vis the velocity vector of the ball's instaneous direction will be greater.
The gun will read only the sine of the angle, not the full velocity vector.
So yes, you will get fall off in your MPH readings as the ball approaches home, but no, the ball is not actually losing speed at that rapid rate. Maybe a little, but not that much.
A 2-seamer will read a greater drop not because of air cushion effect, because that is negligible. The issue is that if some of the ball's forward momentum is transferred to sideways or downward movement, again you will get a resulting reduction in the forward vector. For curves the effect will be even more pronounced.
So based on your hypothesis the more movement a pitch has, the less reliable the gun reading?
quote:Originally posted by Midlo Dad:
My point is this.
Draw yourself a diagram from the side view, where the gun is up in the stands behind home plate. Plot the pitcher's release point, the catcher's mitt location, the path of the ball and the angle from the gun to the ball at various points along the ball's path.
Remember that due to g the ball's path will be parabolic, not linear. So, as the ball reaches home the angle of the gun vis a vis the velocity vector of the ball's instaneous direction will be greater.
The gun will read only the sine of the angle, not the full velocity vector.
So yes, you will get fall off in your MPH readings as the ball approaches home, but no, the ball is not actually losing speed at that rapid rate. Maybe a little, but not that much.
A 2-seamer will read a greater drop not because of air cushion effect, because that is negligible. The issue is that if some of the ball's forward momentum is transferred to sideways or downward movement, again you will get a resulting reduction in the forward vector. For curves the effect will be even more pronounced.
Or, you can read the link I supplied that explains how they come up with those numbers. It has nothing to do with a radar gun.
They take video from the side view at 30 frames per second. They measure the distance the ball travels in a frame. They compare the distance right out of the hand to the distance at home plate. It becomes simple math.
Midlo Dad,
The diagram is OK, but the numbers don't work out. For example, if a radar gun measures the speed out of the pitcher's hand as 90mph, and 82 mph at the plate, to explain that as the effect of the increased downward angle of flight would require that the ball be traveling downwards at 24 degrees from horizontal. That's .45 feet downward for each foot of horizontal travel, which is absurd for a fastball. After all, some peole think (wrongly of course) that a well thrown fastball rises as it crosses the plate!
And, as has been pointed out, there are plenty of Pitch F/X measurements which aren't susceptible to cosine errors that show about the same loss of velocity as a radar gun.
Here's another way to look at this. A half century ago, Lyman Briggs used a vertical wind tunnel to measure the drag on a baseball. He found that the upward wind velocity required to suspend a baseball is between 90 and 100mph, which is conveniently close to pitched ball speeds. So the force of wind resistance on a collegiate or pro fastball is very similar to the force of gravity. That implies the deceleration of a good fastball is quite similar to the acceleration due to gravity-- about 32feet/sec/sec. Works out to 8.5mph for a 90mph fastball-- something of an overestimate because the drag decreases with velocity.
The diagram is OK, but the numbers don't work out. For example, if a radar gun measures the speed out of the pitcher's hand as 90mph, and 82 mph at the plate, to explain that as the effect of the increased downward angle of flight would require that the ball be traveling downwards at 24 degrees from horizontal. That's .45 feet downward for each foot of horizontal travel, which is absurd for a fastball. After all, some peole think (wrongly of course) that a well thrown fastball rises as it crosses the plate!
And, as has been pointed out, there are plenty of Pitch F/X measurements which aren't susceptible to cosine errors that show about the same loss of velocity as a radar gun.
Here's another way to look at this. A half century ago, Lyman Briggs used a vertical wind tunnel to measure the drag on a baseball. He found that the upward wind velocity required to suspend a baseball is between 90 and 100mph, which is conveniently close to pitched ball speeds. So the force of wind resistance on a collegiate or pro fastball is very similar to the force of gravity. That implies the deceleration of a good fastball is quite similar to the acceleration due to gravity-- about 32feet/sec/sec. Works out to 8.5mph for a 90mph fastball-- something of an overestimate because the drag decreases with velocity.
55mom, thank you for that link. I now clearly understand the physics of a fastball; or was that how we reached the moon?
quote:Originally posted by itsrosy:
55mom, thank you for that link. I now clearly understand the physics of a fastball; or was that how we reached the moon?
.
If you watch a season's worth of re-runs I'm sure you'll be able to make the distinction rosy...
...just ask Alice!
.
If you watch a season's worth of re-runs I'm sure you'll be able to make the distinction rosy...
...just ask Alice!
.
quote:Originally posted by 3FingeredGlove:
Midlo Dad,
The diagram is OK, but the numbers don't work out. For example, if a radar gun measures the speed out of the pitcher's hand as 90mph, and 82 mph at the plate, to explain that as the effect of the increased downward angle of flight would require that the ball be traveling downwards at 24 degrees from horizontal. That's .45 feet downward for each foot of horizontal travel, which is absurd for a fastball. After all, some peole think (wrongly of course) that a well thrown fastball rises as it crosses the plate!
And, as has been pointed out, there are plenty of Pitch F/X measurements which aren't susceptible to cosine errors that show about the same loss of velocity as a radar gun.
Here's another way to look at this. A half century ago, Lyman Briggs used a vertical wind tunnel to measure the drag on a baseball. He found that the upward wind velocity required to suspend a baseball is between 90 and 100mph, which is conveniently close to pitched ball speeds. So the force of wind resistance on a collegiate or pro fastball is very similar to the force of gravity. That implies the deceleration of a good fastball is quite similar to the acceleration due to gravity-- about 32feet/sec/sec. Works out to 8.5mph for a 90mph fastball-- something of an overestimate because the drag decreases with velocity.
Very nice 3Finger. Need a job?!? Dang, I had just drawn this all out and was figurin' on how to explain it...but you did much better than I would have.
I figure the worst case scenario, with the gun in the press box there's about a 1 degree differential between the pitcher's mound and homeplate. Negligible.
See you a football game 2-nite? Go Monarchs!
There's no cosine "error" when the ball is moving downward or sideways due to a combination of gravity/spin. The gun is reading the velocity going toward the gun. The overall speed of the ball is the vector sum of the forward and sideways/downward movements but the gun in effect only reads the velocity toward the gun.
For example, a fastball released dead level at 90 mph which reaches the plate going 82 mph will be traveling about 120.27 fps forward and 8.56 fps down as is crosses the plate. It's going down at about 4 degrees as it crosses the plate. The total speed is a whopping 120.57 fps but the gun will read the 120.27 fps that it is moving forward. It is going toward the gun at 82 mph so that's what the gun reads. (Note: This is different from what Midlo was saying. He was saying that some of the forward velocity was being drained off to create velocity in the sideways/downwards direction. This difference is real but tends to be fairly negligible as the velocity change due to spin alone isn't that much. Also in general, the more spin there is the less drag there is so they tend to offset.)
A curveball might be going downwards at a much larger angle as it crosses the plate and the resultant speed of the ball may be a bit higher than the gun reading, but the gun is still reading the velocity toward the gun correctly.
Cosine error only comes into play when the gun is well offline from the path of the ball and it does have to be pretty far offline to be significant.
I often gun the kids from a spot that is about 10' above the plate and only about 20' behind the plate. That means a cosine error of about .77 mph on an 85 mph fastball and that I'll get a 1 mph low reading off the gun more often than not if the ball is released dead level.
Now let's look at the reading I'd get if I was that close to the plate as the ball crosses the plate. Now with a height of 10 ft and a horizontal distance of 20 ft I'd get an angle of 26.6 degrees and a ball with a forward velocity of 80 mph as it crossed the plate would give me a reading of about 72 mph due to cosine error. However, the movement of the ball wouldn't be contributing to that.
So there is a possibility of cosine error affecting gun readings at the plate if the gun is not very far behind the plate at all and offline a significant amount but the movement of the ball doesn't contribute. The reality is that it is very rare for there to be a chance to gun from so close and so far offline that it significantly affects the gun readings at the plate.
One of the funniest examples of cosine error I ever saw was at an A's vs. Giants game where they had the gun setup at almost a 45 degree angle (i.e. 30 feet in the direction of the ball and 30 feet to the side) from the path of the ball. People are almost always surprised at how slowly they throw but the readings they were getting were ridiculously low. That was a real ego buster.
For example, a fastball released dead level at 90 mph which reaches the plate going 82 mph will be traveling about 120.27 fps forward and 8.56 fps down as is crosses the plate. It's going down at about 4 degrees as it crosses the plate. The total speed is a whopping 120.57 fps but the gun will read the 120.27 fps that it is moving forward. It is going toward the gun at 82 mph so that's what the gun reads. (Note: This is different from what Midlo was saying. He was saying that some of the forward velocity was being drained off to create velocity in the sideways/downwards direction. This difference is real but tends to be fairly negligible as the velocity change due to spin alone isn't that much. Also in general, the more spin there is the less drag there is so they tend to offset.)
A curveball might be going downwards at a much larger angle as it crosses the plate and the resultant speed of the ball may be a bit higher than the gun reading, but the gun is still reading the velocity toward the gun correctly.
Cosine error only comes into play when the gun is well offline from the path of the ball and it does have to be pretty far offline to be significant.
I often gun the kids from a spot that is about 10' above the plate and only about 20' behind the plate. That means a cosine error of about .77 mph on an 85 mph fastball and that I'll get a 1 mph low reading off the gun more often than not if the ball is released dead level.
Now let's look at the reading I'd get if I was that close to the plate as the ball crosses the plate. Now with a height of 10 ft and a horizontal distance of 20 ft I'd get an angle of 26.6 degrees and a ball with a forward velocity of 80 mph as it crossed the plate would give me a reading of about 72 mph due to cosine error. However, the movement of the ball wouldn't be contributing to that.
So there is a possibility of cosine error affecting gun readings at the plate if the gun is not very far behind the plate at all and offline a significant amount but the movement of the ball doesn't contribute. The reality is that it is very rare for there to be a chance to gun from so close and so far offline that it significantly affects the gun readings at the plate.
One of the funniest examples of cosine error I ever saw was at an A's vs. Giants game where they had the gun setup at almost a 45 degree angle (i.e. 30 feet in the direction of the ball and 30 feet to the side) from the path of the ball. People are almost always surprised at how slowly they throw but the readings they were getting were ridiculously low. That was a real ego buster.
PG,
I've never really understood why there's a difference between the release velocity of a 4 seam and 2 seam fastball. As long as the fingers are behind the ball and the same effort is put into it the release velocity should be the same. My guess is that it is a combination of the grip not imparting the velocity quite as well and in most cases just not trying to throw a 2 seamer as hard.
I've never really understood why there's a difference between the release velocity of a 4 seam and 2 seam fastball. As long as the fingers are behind the ball and the same effort is put into it the release velocity should be the same. My guess is that it is a combination of the grip not imparting the velocity quite as well and in most cases just not trying to throw a 2 seamer as hard.
We actually do see a few pitchers who throw their 2-seamer with the same velocity as their 4-seamer. For the most part I think the 4-seamer allows the ball to be released at a little more speed just due to the grip.
However, I think the 4-seam (vs. 2 seam)velocity at the plate is usually closer to the out of hand speed. Still considerably less either way, though.
Hey! I'm in over my head when discussing these things with you guys. I know what ends up happening, but can't give scientific reasons why it happens.
However, I think the 4-seam (vs. 2 seam)velocity at the plate is usually closer to the out of hand speed. Still considerably less either way, though.
Hey! I'm in over my head when discussing these things with you guys. I know what ends up happening, but can't give scientific reasons why it happens.
Great read. Even for the non-geeks out there.
HiHardHeat got it exactly right when he said:
Less "drag," more velocity.
and...
In other words, the grip upon release determines the physical properties that will govern the motion of the ball rotating in the air on the way to the plate...its the physics of the rotating ball, with seams in different orientations that lead to the observations of PGStaff while watching young pitchers.
If you really want to dig very deep into this, the following link is a study by a colleague on this topic. Not the easiest to read, but it basically says the same thing. One of the more interesting parts include the discussion of the so-called "rising fastball." Good geek stuff.
Sports Ball Aerodynamcs
quote:The grip on the ball has a lot to do with it. The reason that a 4-seam FB doesn't drop in velocity as fast as a 2-seam FB is that that seams trap a boundary layer of air against the ball. That reduces the amount of drag.
Less "drag," more velocity.
and...
quote:...it relates more to the properties of rotating bodies in a fluid medium.
In other words, the grip upon release determines the physical properties that will govern the motion of the ball rotating in the air on the way to the plate...its the physics of the rotating ball, with seams in different orientations that lead to the observations of PGStaff while watching young pitchers.
If you really want to dig very deep into this, the following link is a study by a colleague on this topic. Not the easiest to read, but it basically says the same thing. One of the more interesting parts include the discussion of the so-called "rising fastball." Good geek stuff.
Sports Ball Aerodynamcs