Major League Baseball receives report on increased home run rate

MLB

The committee concluded that the increase in home run hitting since the 2015 season was due, at least in part, to a change in the aerodynamic properties of the baseball (i.e., reduced drag for given launch conditions, as opposed to a change in launch conditions). That conclusion is supported by their analysis of Statcast™ data, a physics-based model that the Committee developed, and laboratory testing of game-used baseballs from before and after the increase in home run rate. The Committee did not find any change in the size, weight, seam height, or COR of the baseball that would explain the increase in home runs. Though the Committee was unable to conclusively prove the exact cause of the reduced drag since the 2015 season, they offered hypotheses including that the rubber pill may be more centered within the baseball since 2015 and that the ball may be staying rounder while spinning since the 2015 season.

IMO The game is much more fun to watch now that homeruns have increased so much. It is very interesting for ats members cause there is a genuine mystery here in which scientist are unable to pinpoint to the cause. They compared the baseballs before and after the surge all the way down to visiting the ball plant.

Every new baseball is rubbed with the same rubbing mud nearly since the game started and the mud is sourced from a secret location. That is really the only unknown factor i can find in the case. Other than that everything is out in the open and no changes have been found. Some teams are even opting now for humidors to store their balls in.

What say you ats what is responsible for the serious increase in home runs?

a reply to: howtonhawky

Though the Committee was unable to conclusively prove the exact cause of the reduced drag since the 2015 season, they offered hypotheses including that the rubber pill may be more centered within the baseball since 2015 and that the ball may be staying rounder while spinning since the 2015 season.

OMG Baseball is so boring!

IMO The game is much more fun to watch now that homeruns have increased so much.

Exactly! That's why they put the little rubber pill wherever...or whatever...So that baseball would be less boring!

a reply to: Sookiechacha

If you have not watched a game in a couple yrs it is now a bit more interesting.

Breaking all the home records with no change in method in a game that has seen very much stability in the number of home runs hit every year.


ETA Keep in mind the rubber pill has not changed even though the author speculates such they actually cut open balls from before and after the increase and no physical change was noted.

If they want to modernize MLB they need to make it more like fast pitch softball. Cut the games to 7 innings and put the same run rules in effect as the NCAA so that a team ahead by 8 runs after 5 innings ends the game.

Purists might hate it, but frankly I can’t watch 9 innings of baseball like I used to when I was younger. After coaching softball it is nice to have an escape from blowouts after five innings and to get home before bedtime.

a reply to: Metallicus

I do not think they will be changing anytime soon.

What about the sudden increase in home runs and scoring.

The league got some of the brightest around to look into the reason for such but no answers can be found.

All the old records are being smashed.

Fastest pitch

Also some pitchers claim to have noticed last year that the seams are causing more ware on their hands.

Again scientist have looked and no changes to the ball or any of the process in making them.

Maybe the pitchers are not what they used to be.

originally posted by: TinfoilTP
Maybe the pitchers are not what they used to be.

They hired experts to look at all the factors involved in a scientific manner.

In the link they name them and seems like highly educated group that could come to no conclusion.


MANDELA EFFECT?

Home run hitters make more money than guys with 400 batting averages.
The result is men swinging for the fences.

a reply to: howtonhawky

Finally an interesting topic that is completely politics free!

The Executive Summary is an interesting read.

Well designed and well controlled tests. Lots of research and information about both pitching and hitting was taken into consideration. A sophisticated statistical model was used to examine a lot of intersecting parameters. Well written report by a best-selling science author.

The committee was made up of scientists and engineers from some of the top universities in the country; including MIT, CalTech, and Stanford. Two separate laboratories corroborated each other's results.

MLB spent a lot of money on this. And the simple answer is the ball has a slightly lower drag coefficient:

Both procedures performed–the experimental tests at WSU and the mathematical analysis of StatCast data–indicate that the drag coefficient has changed by approximately 0.0153 since 2015, an amount sufficient to have caused the home run surge.

But the real mystery is how did the ball itself change to produce this effect?

I'm not sure, but I think I saw an episode of How It's Made that showed this manufacturing process. The Executive Summary document itself details the rather exacting process used to produce and validate each ball. Assuming that the chemical composition of the raw materials hasn't changed, the only non-deterministic element of the manufacturing process is the sewing of the seams in the ball. That procedure is done by hand, and is therefore subject to variations in human performance.

It's interesting to see how the MLB is responding to this. Requiring humidors, specifying mud rubbing procedures, and other actions to attempt to guarantee ball-state consistency. In a multi-billion dollar industry, there are certain things you just can't leave to chance.

I don't watch baseball these days. But, I used to when I was a kid. I remember the difference in watching an outfielder damn near run up the side of the outfield wall to catch a fly and seeing him do the same thing only to see that ball gently glide just beyond his reach. It was always just a little more exciting to see such effort thwarted; even if it wasn't in my team's favor.



-dex

originally posted by: Bluntone22
Home run hitters make more money than guys with 400 batting averages.
The result is men swinging for the fences.

They looked at this as well. They were able to break down all of the physics involved in hitting home-run balls. Then they examined the various players' swinging techniques to see if there had been enough changes across the board to account for the home-run statistics changes. There were some slight variations, but nothing significant enough to account for the increase.

And the statistical changes were distributed relatively evenly across the field of hitters. So, a "rising tide lifts all boats" scenario is play. Which points to an environmental factor, rather than a human procedural factor.

-dex

More domed stadiums being built, means less environmental impact on the ball due to no natural wind.

a reply to: Krakatoa

I like that possibility.

Another may be a change in training. Did something change that is not seen as significant, such as a shift towards a slightly different swing or stance that was widely accepted by all clubs.

In many sports with so much money at stake, it may be a change in training regimes or perhaps some psychology was implemented.

The change in home runs is significant but the minor difference in flight dynamics is simply keeping the ball aloft for a tiny extra time. Because of the fence, you now score more home runs.

Check the sport's headlines in 2014/2016 to see if something stands out. Everyone may have forgotten a minor change made years ago.

P

originally posted by: pheonix358
a reply to: Krakatoa

I like that possibility.

Another may be a change in training. Did something change that is not seen as significant, such as a shift towards a slightly different swing or stance that was widely accepted by all clubs.

In many sports with so much money at stake, it may be a change in training regimes or perhaps some psychology was implemented.

The change in home runs is significant but the minor difference in flight dynamics is simply keeping the ball aloft for a tiny extra time. Because of the fence, you now score more home runs.

Check the sport's headlines in 2014/2016 to see if something stands out. Everyone may have forgotten a minor change made years ago.

P

There are many environmental factors that are eliminated with a domed stadium. In addition to lack of wind there are: No rain, no cold, no sun in the eyes, no shade to reduce visibility, no passing cloud cover, no uncontrolled humidity/dryness, and I'm sure there are more that I did not mention.

Alone, each is negligible, but added together, they become a measurable factor in the game. A factor, IMO, that takes away from the game and makes it easier for the participants since they do not have to learn to adjust to these factors and changing adversities during play.

originally posted by: Krakatoa
More domed stadiums being built, means less environmental impact on the ball due to no natural wind.

There's only one domed stadium in MLB, the rest are retractable roofs that are opened when it's not raining.

originally posted by: AugustusMasonicus

originally posted by: Krakatoa
More domed stadiums being built, means less environmental impact on the ball due to no natural wind.

There's only one domed stadium in MLB, the rest are retractable roofs that are opened when it's not raining.

I was including the retractable ones in the list of "domed" stadiums. They are also closed when it is 100F out, or extremely cold, etc...

a reply to: DexterRiley


It is a very mysterious topic glad to see someone get's it.

I agree with your post but you seem to be missing that the pitching speeds have not changed and it seems likely that in order to see such an increase in home runs that the same factor causing such would have a noticeable impact on the pitching speeds.

I only heard of two pitchers making the claim of the balls in the last couple yrs being rougher on their hands.

Such difference in ball travel after being hit would also cause pitching fluctuation.

Mandela effect??

a reply to: howtonhawky

I got a little long winded. So this reply is split across two different posts. It's an interesting thought experiment.

I agree with your post but you seem to be missing that the pitching speeds have not changed and it seems likely that in order to see such an increase in home runs that the same factor causing such would have a noticeable impact on the pitching speeds.

I agree that one would expect a linear increase in pitching speed commensurate with an increase in exit speed after the hit, with a resultant increase in travel distance.

There's an interesting article on Popular Mechanics that discusses some of the more interesting aspect of the physics of a home run ball. Including how the ball's spin velocity, direction, and angle are major factors in the distance a batted ball travels.

My first thought was that the distance traveled of a pitched ball, relative to the distance traveled of a home run hit ball is significantly less. The distance from the pitcher's release point to the bat's impact point is about 50 feet or so. Whereas, the distance traveled of a home run ball can be over 400 feet. Unfortunately, this theory breaks down because pitching velocity and exit speed are both determined based on a standardized set of cameras mounted at each ballpark specifically for the purpose of measuring those speeds. So, those instantaneous velocity measurements are independent of the distance traveled by the ball.

the pitchf/x system which uses permanently installed video cameras in each MLB park to track the pitched baseball. The very same cameras can also be used to track the initial part of the batted-ball trajectory, from which the initital batted-ball velocity, vertical launch angle, and horizontal spray angle can be determined.

The Carry of Fly Ball

Dr. Alan Nathan began looking at this issue back in 2016 after it was first noticed that post the All Stars game in 2015, the number of home runs per batted ball had increased. He determined that there was an approximate increase in exit speed of 1.5 mph for home run hits. He then applied this model to data from an earlier period representative of a lower home run hit rate. It resulted in a good fit of the remodeled data to the actual measured data of the period representative of the higher home run hit rate.

Later results derived from testing and analysis performed by the MLB committee were unable to confirm this early analysis. However, the statistical modeling he performed in his earlier studies does provide a basis for exploring why there is no noticeable change in pitching velocity relative to the the distance traveled of the baseball.

Dr. Nathan later responded to a question concerning the effect of pitching speed relative to batted ball hit distance. He demonstrated that there was a 5 to 1 ratio in favor of increases to exit speed versus increase in pitching speed. In other words, for the pitch speed increase to have any positive effect on the distance the ball travels, the magnitude of the increase would have to be significant.

Therefore, we are given:
1. We know the most interesting end result of the pitch-hit-land process is a longer travel distance.
2. Energy is input into the system during the pitching and hitting phases.
3. A 5:1 ratio exists for pitching/hitting velocity changes to changes in distance traveled.
4. A calculated 1.5 mph increase in exit speed has resulted in the increase in the number of home runs.

If we assume:
1. A 101.5 mph exit speed. This is a 1.5% increase in speed over a 100 mph exit speed. (Just using this value to make the math work out evenly) Let's say this is the value needed to increase ball speed to the home run level.
2. For our purposes, lets say that there is a direct linear relationship between the energy input to a phase and the resulting velocity.
3. The amount of energy input to the hitting phase is increased by 1.5%, while the input to the pitching phase remains unchanged, results in an exit velocity of 101.5 mph.
4. The amount of energy input to the pitching phase is increased by 7.5%, while the input to the hitting phase remains unchanged results in an exit velocity of 101.5 mph.
5. The actual contributing factor is not related to energy input to the system from either phase; rather it's related to a systemic factor. Based on the report, this factor is actually the drag coefficient of the ball.

Therefore:
The magical distance-traveled increase factor is distributed evenly during all phases of the ball flight from the time the pitcher releases the ball to the time it lands. However, the proposed drag coefficient decrease affects the ball's aerodynamics properties, which are most applicable during the ball travel once it has exited the hitting phase. And we likely wouldn't notice anything during the power phases.

However, if we were to pursue the energy input model and consider the energy input increase in the system to be uniform during the power phases. We would see most of the velocity increase during the hitting phase at approximately 1.5%, while any velocity increase in the pitching phase would only amount to 0.3% or less. (1.5%/5) That amount of change is likely within the margin of error of the calculations, and likely wouldn't emerge from the noise. So we wouldn't see it. (Note that we would need to use a proper integration to determine the actual velocity increase per phase, but this is close enough for our purposes here.)


--Continued--

-dex

a reply to: howtonhawky

--Continued--

I only heard of two pitchers making the claim of the balls in the last couple yrs being rougher on their hands.

It's interesting that the roughness of the ball's surface could play a part in the aerodynamic properties of the ball. A non-uniform surface would increase the drag. A smooth surface would decrease the drag. However, a uniformly dimpled surface like a golf ball optimizes the drag coefficient.

I wonder if some subtle change in the surface of the leather used to make the outer covering of the baseball could produce this better drag coefficient. Perhaps there's a more uniform microscopic-level dimpling. Or perhaps some slight change in the depth of the surface imperfections happen to be opportunistically more ideal than in leather that was sourced in the past.

I haven't read all the way through the complete test results, but I wonder whether they performed microscopic and molecular analysis of the raw materials used in making the baseballs. Microscopic analysis of the leather's surface, including cavity depth and uniformity of their distribution, should reveal a product that is not substantially different from that used in past manufacturing.

And it goes without saying that the ball's stitches are a major factor in aerodynamic drag. I would think that changes not only in the sewing process, but also the material used for the stitches would have a non-trivial effect on the drag coefficient. And changes of that magnitude may be detectable by pitchers with a great deal of experience in handling a baseball.

Mandela effect?

I don't know. Maybe there's some kind of bit rot in the Matrix Operating System.


-dex

a reply to: DexterRiley

Later results derived from testing and analysis performed by the MLB committee were unable to confirm this early analysis. However, the statistical modeling he performed in his earlier studies does provide a basis for exploring why there is no noticeable change in pitching velocity relative to the the distance traveled of the baseball.

If the change in flight is 1.5% at 400 feet then at 50' we would see a .1875% change at the mound and that would likely not be noticed by most?

Great post.

It is amazing how such a small change could change the game so much.