## Poll

 I enjoy sports. 37 votes (62.71%) I hate sports. 2 votes (3.38%) I have no time for sports. 5 votes (8.47%) If you can bet on it, I love it. 3 votes (5.08%) I am a poor sport. 9 votes (15.25%) "It ain’t over till it’s over." (YB) 2 votes (3.38%) I am a dogmatist! 1 vote (1.69%)

59 members have voted

gordonm888
Joined: Feb 18, 2015
• Posts: 4409
May 30th, 2023 at 4:34:18 PM permalink
Quote: tuttigym

gordon888, Please answer a couple of questions that might help me clarify my thinking.

1. It seems that every time a HR is hit the "exit velocity" is given. Is "exit velocity" the product of pitch speed and bat speed?

2. To my knowledge, bat speed is never given. For me, that info is more important than "exit velocity." Here is why: a ground ball with X "exit velocity" is never going to leave the park, so that info is, for me irrelevant. On the other hand, a 400 foot HR could be the result of different bat speeds depending upon the pitch speed. Do you agree? (For now, let's forget the launch angle)

3. Wouldn't it make sense to determine the bat speed of every HR against the different types of pitches and pitch speed for training purposes? There may be many players that are deficient in average bat speed that could benefit from such info and train accordingly. Do you agree?

Based on your answers, I will comment and perhaps expand my thoughts.

tuttigym
link to original post

The exit

I would think that the exit velocity of a batted baseball (that is struck squarely by a bat) would depend upon:
1. Pitch speed: which shows up as pitched ball momentum and translational energy.
2. The momentum of the bat = mass * velocity. A heavier bat would result in faster exit velocity of a batted ball.
3. The force (or energy) of the swing F = m v2; which depends upon how hard the player is driving the ball at the moment of contact. this is not only arm strength but how much torque the batter's body had as he swings the bat.
4. The elasticity of the ball. It has been shown that baseballs that are dry (say, because they are at high altitude such as Denver) are less elastic and therefore almost all of the force/momentum of the bat is converted into kinetic energy; i.e. into ball speed. However, baseballs that are 'humid' will absorb some of the energy by compression and deformation, resulting in a lower exit velocity.
5. To a much lesser extent, the elasticity of the bat itself. Bats can absorb some of the energy of the bat/ball collision as both heat and elastic deformation. This is why aluminum bats are different than wood bats - a hollow aluminum bat has different mechanical.
properties. But I imagine that the variability in materials properties of MLB bats is fairly low (although I think that there are at least two
different types of wood that MLB bats can be made of.)
6. To a small extent the spin of the pitched ball, because its rotational energy is available to be converted into post-collision translational energy. However rotational energy of the baseball is << the translational energy of the pitched baseball, so this might be ignoredin a approximate analysis.
7. Similarly, if the pitch is curving or moving from sideways in its trajectory, that will also have a small effect on the exit velocity.

Striking the ball squarely
There is a lot hidden in the assumption that the ball is hit squarely by the bat. If the batter is out in front of the pitch, or is a bit late hitting the pitch, then the bat head is not moving in a direction directly opposed to the velocity of the ball, and the physics will be different. If the bat head is a bit high or a bit low relative to the position of the pitched ball then the ball will be driven into the ground or popped up - and also the exit speed would be diminished.

The height of the pitch relative to height of the swing will also be important. These factors are all submerged in the assumption that the pitched ball is struck "squarely" by the bat.

Regarding questions #2 and #3, I don't know. I imagine that hitting the ball squarely and with perfect timing is very important. I think that batters do better at hitting home runs in batting practice (and home run competitions) because the pitch is thrown at relatively low speeds which allow the batters to time their swings better -even though a higher speed pitch has more energy to contribute to the bat ball collision. So there is a lot more than "bat speed" that goes into this.
So many better men, a few of them friends, are dead. And a thousand thousand slimy things live on, and so do I.
gordonm888
Joined: Feb 18, 2015
• Posts: 4409
May 30th, 2023 at 4:34:18 PM permalink
Quote: tuttigym

gordon888, Please answer a couple of questions that might help me clarify my thinking.

1. It seems that every time a HR is hit the "exit velocity" is given. Is "exit velocity" the product of pitch speed and bat speed?

2. To my knowledge, bat speed is never given. For me, that info is more important than "exit velocity." Here is why: a ground ball with X "exit velocity" is never going to leave the park, so that info is, for me irrelevant. On the other hand, a 400 foot HR could be the result of different bat speeds depending upon the pitch speed. Do you agree? (For now, let's forget the launch angle)

3. Wouldn't it make sense to determine the bat speed of every HR against the different types of pitches and pitch speed for training purposes? There may be many players that are deficient in average bat speed that could benefit from such info and train accordingly. Do you agree?

Based on your answers, I will comment and perhaps expand my thoughts.

tuttigym
link to original post

I would think that the exit velocity of a batted baseball (that is struck squarely by a bat) would depend upon:
1. Pitch speed: which shows up as pitched ball momentum and translational energy.
2. The momentum of the bat = mass * velocity. A heavier bat would result in faster exit velocity of a batted ball.
3. The force (or energy) of the swing F = 1/2*m v2; which depends upon how hard the player is driving the ball at the moment of contact. this is not only arm strength but how much torque the batter's body had as he swings the bat.
4. The elasticity of the ball. It has been shown that baseballs that are dry (say, because they are at high altitude such as Denver) are less elastic and therefore almost all of the force/momentum of the bat is converted into kinetic energy; i.e. into ball speed. However, baseballs that are 'humid' will absorb some of the energy by compression and deformation at the moment of impact, resulting in a lower exit velocity.
5. To a much lesser extent, the elasticity of the bat itself. Bats can absorb some of the energy of the bat/ball collision as both heat and elastic deformation. This is why hollow aluminum bats are different than solid wood bats - a hollow aluminum bat has different mechanical properties. But I imagine that the variability in materials properties of MLB bats is fairly low (although I think that there are at least two different types of wood that MLB bats can be made of.)
6. To a small extent the spin of the pitched ball, because its rotational energy is available to be converted into post-collision translational energy. However rotational energy of the baseball is << the translational energy of the pitched baseball, so this might be ignored in a approximate analysis.
7. Similarly, if the pitch is curving or moving from sideways in its trajectory, that will also have a small effect on the exit velocity.

Striking the ball squarely
There is a lot hidden in the assumption that the ball is hit squarely by the bat. If the batter is out in front of the pitch, or is a bit late hitting the pitch, then the bat head is not moving in a direction directly opposed to the velocity of the ball, and the physics will be different. If the bat head is a bit high or a bit low relative to the position of the pitched ball then the ball will be driven into the ground or popped up - and also the exit speed would be diminished.

The height of the pitch relative to height of the swing will also be important. These factors are all submerged in the assumption that the pitched ball is struck "squarely" by the bat.
******************************
Regarding questions #2 and #3, I don't know. I imagine that hitting the ball squarely and with perfect timing is very important. I think that batters do better at hitting home runs in batting practice (and home run competitions) because the pitch is thrown at relatively low speeds which allow the batters to time their swings better -even though a higher speed pitch has more energy to contribute to the bat+ball collision. So there is a lot more than "bat speed" that goes into this.
So many better men, a few of them friends, are dead. And a thousand thousand slimy things live on, and so do I.
lilredrooster
Joined: May 8, 2015
• Posts: 5641
May 31st, 2023 at 2:42:09 AM permalink
.

Mark McGwire & Barry Bonds before and after steroids:

.

.
"believe half of what you see and none of what you hear" - Edgar Allan Poe
mcallister3200
Joined: Dec 29, 2013
• Posts: 3398
May 31st, 2023 at 4:56:28 AM permalink
Thing is, take pictures of 30 non steroid users at age 23, then age 35 and look at the frequency of blow ups…….
lilredrooster
Joined: May 8, 2015
• Posts: 5641
May 31st, 2023 at 5:05:25 AM permalink
Quote: mcallister3200

Thing is, take pictures of 30 non steroid users at age 23, then age 35 and look at the frequency of blow ups…….
link to original post

yeah, but I think you're talking about guys getting older and getting fat - happens to so many
these guys are not fat

take another look at McGwire's right forearm - gigantic

.
"believe half of what you see and none of what you hear" - Edgar Allan Poe
billryan
Joined: Nov 2, 2009
• Posts: 14946
May 31st, 2023 at 5:07:42 AM permalink
Big Mac was an Olympian and hit 49 home runs his rookie year. After several injury-plagued seasons, he began taking various things to revive his career. He was a lanky third baseman who occasionally filled in at short, iirc.
The difference between fiction and reality is that fiction is supposed to make sense.
lilredrooster
Joined: May 8, 2015
• Posts: 5641
May 31st, 2023 at 5:19:41 AM permalink
Quote: billryan

Big Mac was an Olympian and hit 49 home runs his rookie year. After several injury-plagued seasons, he began taking various things to revive his career
link to original post

he hit 70 homers in '98 - a 43% increase over his rookie year total - and he hit 65 in '99

the dude was crushing Babe Ruth - looking at just that stat - the most the Babe ever hit in one year was 60

who is going to believe that without steroids Mac was in the same league as Babe Ruth_______?_________methinks not too many

.
"believe half of what you see and none of what you hear" - Edgar Allan Poe
billryan
Joined: Nov 2, 2009
• Posts: 14946
May 31st, 2023 at 5:31:18 AM permalink
Quote: lilredrooster

Quote: billryan

Big Mac was an Olympian and hit 49 home runs his rookie year. After several injury-plagued seasons, he began taking various things to revive his career
link to original post

he hit 70 homers in '98 - a 43% increase over his rookie year total - and he hit 65 in '99

the dude was crushing Babe Ruth - the most the Babe ever hit in one year was 60

who is going to believe that without steroids Mac was in the same league as Babe Ruth_______?_________methinks not too many

.
link to original post

If Babe had spent some time in the gym, he might have been popping numbers like that, as well. Steroids don't make forearms like that. They give you the ability to build them, but you still have to put in an incredible amount of work. They are illegal, and using them is most certainly cheating, but you don't just pop a pill and turn it into the Hulk. They are called performance enhancing, not performance creating.
The difference between fiction and reality is that fiction is supposed to make sense.
tuttigym
Joined: Feb 12, 2010
• Posts: 1540
May 31st, 2023 at 6:38:08 AM permalink
Quote: gordonm888

Quote: tuttigym

gordon888, Please answer a couple of questions that might help me clarify my thinking.

1. It seems that every time a HR is hit the "exit velocity" is given. Is "exit velocity" the product of pitch speed and bat speed?

2. To my knowledge, bat speed is never given. For me, that info is more important than "exit velocity." Here is why: a ground ball with X "exit velocity" is never going to leave the park, so that info is, for me irrelevant. On the other hand, a 400 foot HR could be the result of different bat speeds depending upon the pitch speed. Do you agree? (For now, let's forget the launch angle)

3. Wouldn't it make sense to determine the bat speed of every HR against the different types of pitches and pitch speed for training purposes? There may be many players that are deficient in average bat speed that could benefit from such info and train accordingly. Do you agree?

Based on your answers, I will comment and perhaps expand my thoughts.

tuttigym
link to original post

The exit

I would think that the exit velocity of a batted baseball (that is struck squarely by a bat) would depend upon:
1. Pitch speed: which shows up as pitched ball momentum and translational energy.
2. The momentum of the bat = mass * velocity. A heavier bat would result in faster exit velocity of a batted ball.
3. The force (or energy) of the swing F = m v2; which depends upon how hard the player is driving the ball at the moment of contact. this is not only arm strength but how much torque the batter's body had as he swings the bat.
4. The elasticity of the ball. It has been shown that baseballs that are dry (say, because they are at high altitude such as Denver) are less elastic and therefore almost all of the force/momentum of the bat is converted into kinetic energy; i.e. into ball speed. However, baseballs that are 'humid' will absorb some of the energy by compression and deformation, resulting in a lower exit velocity.
5. To a much lesser extent, the elasticity of the bat itself. Bats can absorb some of the energy of the bat/ball collision as both heat and elastic deformation. This is why aluminum bats are different than wood bats - a hollow aluminum bat has different mechanical.
properties. But I imagine that the variability in materials properties of MLB bats is fairly low (although I think that there are at least two
different types of wood that MLB bats can be made of.)
6. To a small extent the spin of the pitched ball, because its rotational energy is available to be converted into post-collision translational energy. However rotational energy of the baseball is << the translational energy of the pitched baseball, so this might be ignoredin a approximate analysis.
7. Similarly, if the pitch is curving or moving from sideways in its trajectory, that will also have a small effect on the exit velocity.

Striking the ball squarely
There is a lot hidden in the assumption that the ball is hit squarely by the bat. If the batter is out in front of the pitch, or is a bit late hitting the pitch, then the bat head is not moving in a direction directly opposed to the velocity of the ball, and the physics will be different. If the bat head is a bit high or a bit low relative to the position of the pitched ball then the ball will be driven into the ground or popped up - and also the exit speed would be diminished.

The height of the pitch relative to height of the swing will also be important. These factors are all submerged in the assumption that the pitched ball is struck "squarely" by the bat.

Regarding questions #2 and #3, I don't know. I imagine that hitting the ball squarely and with perfect timing is very important. I think that batters do better at hitting home runs in batting practice (and home run competitions) because the pitch is thrown at relatively low speeds which allow the batters to time their swings better -even though a higher speed pitch has more energy to contribute to the bat ball collision. So there is a lot more than "bat speed" that goes into this.
link to original post

Thank you all for taking the time to answer my questions. I will need a little time to digest and possibly inquire more.

My most basic question is: Why is no bat speed at impact provided with the same frequency at "exit velocity"? Whether or not the pitched ball is hit "squarely," and if the resultant collision results in a HR, measuring the bat speed along with the launch angle, which is also reported, would, for me, provide more clarity.

More later, but thanks again.

tuttigym
lilredrooster
Joined: May 8, 2015
• Posts: 5641
May 31st, 2023 at 12:55:43 PM permalink
.
interesting - to me anyway

a comparison (lifetime) Barry Bonds to Babe Ruth

without discounting the cheating advantage Bonds gained from steroids

________________Barry Bonds________________________________The Babe

BA______________ .298_______________________________________.342
OBP_____________.444_______________________________________.474_____________(On Base %)
SLG______________.607_______________________________________.690____________ (total bases per at bat)
HRs per game_____.255_______________________________________.285
RBI per game_____ .668_______________________________________.884

and many not be aware of how great a Pitcher The Babe was before it was decided he would be more valuable elsewhere

he went 94-46 winning 67.1% with a 2.28 era

𝙏𝙃𝙀 𝘽𝘼𝘽𝙀 𝙒𝘼𝙎 𝙏𝙃𝙀 𝙆𝙄𝙉𝙂 𝙊𝙁 𝙏𝙃𝙀 𝙒𝙊𝙍𝙇𝘿

.
Last edited by: lilredrooster on May 31, 2023
"believe half of what you see and none of what you hear" - Edgar Allan Poe