Groundballs Turn Into Homeruns: Truth Or Myth?

A commonly used old school coaching idea that has bothered me for a long time is that “ground balls turn into home runs.” I’ve pulled out my hair many times after hearing things like this. But now, here I am writing an article that will discuss how, when applied right, that actually is true. Don’t freak out, I haven’t changed the way I think the swing should happen only altered where it is executed in a game setting.

Lets first establish that I DO NOT WANT HITTERS TO HIT GROUND BALLS IN GAMES. That wouldn’t be a smart outcome for me to desire. The graph below should do a great job of illustrating why launch angle is important.    

Credit to @tangotiger on twitter for the awesome graphic, you can check out his website here  Y-Axis: wOBA is “Weighted On-Base Average”  It’s a very accurate measure of how valuable a player is offensively much more so than OPS. The calculation is pretty complex so if you’d like to read more about it please check out this article on fangraphs wOBA Defined. For our purposes, just know that the higher the wOBA the better.

As you can see above, the same launch angle produces different results as velocity changes; also the same velocity can produce different results as launch angle changes. So it’s not as simple as fly-balls vs ground balls. We all want run producing value on offense. How do I want to accomplish that? Hit the ball where the other team can’t make an out, and if it’s possible for the hitter to also hit that ball very far (possibly over the fence) then that is even better, obviously. Whatever Exit Velocity box (in above graph) you fall into should govern your desired launch angle. Players that can hit the ball 100MPH+ should hit the ball high because that is how they give their team the most value. But younger players may have a max Exit Velocity of 80 MPH, If that’s the case, they should hit the ball between 16-24 degrees. Now please understand that this graph doesn’t account for softball or youth baseball, so all the numbers would change as field and player size change (also MLB data was used to develop this graph which we don’t have for youth baseball and softball). To summarize my view on in game hitting I’ll use a few non-grammatically correct words, “Hit it where they ain’t.” When you hit a ground ball, it’s hard hit it to the open areas of the field at levels beyond middle school.

Ok, so I spent the whole first part of this article explaining why I don’t want ground balls, and now I’m going to do a complete left turn and explain why hitting them while you train actually does have a ton of value.

On its face, the idea of ground balls turning into home runs is absolutely is ludicrous, designing your swing to hit a hard ground ball isn’t good for anyone, I’ve talked about this endlessly, the ball is traveling downhill, thus we should swing uphill matching it’s path if possible. The movement of the swing should be designed to hit the ball hard over the infield (softball we want to swing uphill a little less but there isn’t much difference).

You’re probably thinking, “ok, so what are you getting at? You want to practice hitting grounders but you want to swing like you’re trying to drive the ball over the infield?”

Yes, exactly.

I promise I’ll tie this all together. Stay with me.

Here’s a scientific reality that we all have to come to terms with, a hitter can’t actually see the ball for the last 10 feet or so as it approaches the plate. A pitched ball it’s moving too fast. Here’s a pretty old, but still relevant article about just that. Eye on the ball NY Times 1984

Scientists had an understanding of this as early as 1954. Here’s an excerpt from a 1954 Sports Illustrated Article entitled “You Can’t Keep Your Eye On The Ball”

“The truth is that baseball hitters never do see the ball when they swing at it. They lose sight of it anywhere from 8 to 15 feet away from home plate. Proof that the batter cannot follow a pitch all the way home comes from two physical-education researchers at the University of Illinois, Dr. Alfred W. Hubbard and Charles N. Seng, who took motion pictures of 29 major-league hitters in action.


This could bring us down a rabbit hole about turning your head/nose on every pitch. We’ll do that soon, but not today.

What does this mean for hitters? It means that when the ball reaches about 10 feet away from home plate a hitter is forced to guess where they expect that ball to be when it reaches where their bat can run into it. Often a hitter is wrong about where they think the ball is going to end up. What forces them to be wrong about the expected location of a pitch? Their inability to see the last 10 or so feet, coupled with the velocity, spin rate and spin direction of the pitch.

Let’s simply address velocity first, a ball thrown 100 MPH and a ball thrown 90 MPH will reach the plate at different times. And generally speaking, a 90 MPH pitch will drop more than a 100 MPH pitch because gravity has more time to act on it (and other reasons we’ll get into later). So if no adjustment is made, when a hitter sees a slower pitch they will tend to swing a little early, and a little high. When a pitch is faster, hitters tend to swing late and low.

Now let’s talk about spin rate and spin direction. In order to understand how spin on the pitch affects a hitter you first need to understand what what Magnus Force is and how it can affect the path of the spinning ball. I made a very simplified video to explain it below.

If you want to watch a smarter, non baseball/softball specific video this is a good one.

In my video, I talk about the difference between a fastball that spins backwards and a curveball that spins forwards, the fastball rises relative to what the expected path of the pitch is and the curveball drops. This is all due to spin rate and direction of the pitch. While it’s obvious that a curveball will drop because it’s spinning forward, what less obvious and arguably more difficult for a hitter to deal with is a pitch like a change-up. Change ups have a similar spin direction as a fastball but just is just spun backwards less, and thrown slower, resulting in the ball dropping in a more subtle but effective way.

Notice how on Scherzer’s all of these hitters miss underneath the ball. That’s because he  1) throws the ball hard and 2) has a high spin rate on his 4 seam fastball. His average spin rate on his 4 seam fastballs in 2018 was 2486 RPM (Baseball Savant) or 16.7 rotations per pitch – 9% faster than the 2018 league average 15.3 rotations per pitch. Meaning his ball rises above where the hitter expects the ball to be. This doesn’t mean the ball is actually rising It means it’s dropping less than it is expected to.

Notice how in each of these change ups by Johnny Cueto the hitter misses over the ball, that’s because 1) the pitch is thrown slower and 2) he has a low spin rate on his change up which makes the ball drop more than expected. Cueto’s 2018 changes ups spin at an average of 1481 RPM, 11.5 rotations per pitch, 12% slower than the league average change up (Baseball Savant).

All of these hitters in the above GIFs thought the ball was going to end up in a different location than it ultimately did. What does this mean? In high level baseball and softball you can’t always trust what your eyes tell you the ball is going to be. A hitter can’t see the ball for the last 10 feet (sometimes more) so being stubborn about where you think the ball is going to be is foolish, and will get you out during high level competition.

Below is an interview between Alex Bergman of the Astros and Alex Rodriguez typically I’m not a fan of ARod but he does a nice job in the this interview of letting Bregman do the talking and explain how the Astros utilize spin rate data to help them hit better.

In the video, the Bregman talks about this term hop this means how much higher the ball ends up relative to where your eyes perceive it to be. It was hard to find any of info on how the astros make this calculation, but I’m going to make a guess and say that the hop number is probably calculated based on where the ball would end up if the spin rate was the league average for that pitch type. So for the sake of keeping things simple, let’s say that pitchers that are able to rotate the ball 15.3 times on their seam fastball (league average) have a hop of 0 inches, since this is what’s perceived as normal to an MLB Hitter. Once again hop is calculated might not be accurate and probably isn’t. The message that I’m getting across is that all changes in spin rate is relative to what you are used to as a hitter.

(If anyone knows how hop is actually calculated and normalized please send me an email [email protected] I’m happy to edit the above paragraph and give you credit)

If Max Scherzer came and pitched in your son’s 14U game the amount of hop he would have on his fastball relative to what your son is used to seeing would be huge. He spins the ball 9% more than the average pitcher 16.7 rotations per pitch for Max vs 15.3 rotations per pitch for the average MLB Pitcher. If your son is used to seeing the ball rotated only 10 times per pitch, Scherzer’s 16.7 rotations per pitch would be a 67% increase, and he might miss under the ball by 2 feet.

Ok, so all this information is good to have but you’re probably thinking, “how can my son or daughter us this information to help them become a better hitter?”

Well it’s important to know that the best hitter’s are not married to where their eyes think the ball is (this is either conscious or subconscious), because they could be wrong and probably are. Let’s imagine that you hit 4th on your 14U team, the game just started and your team’s leadoff hitter his up and he works a walk after fouling 4 balls straight back to the backstop. Then the number 2 hitter pops the ball up high to the shortstop. Next the 3 hitter Strikes out swinging through a fastball. Now you’re up and the pitcher throws you a fastball.

Where are you going to aim? If you aim in the same spot that you always do, you’ll likely have the same result as the 3 hitters that went up before you.

Since you’ve already seen your teammates miss under the ball you already know you need to aim for the top of the ball to hit the ball in the desired location.

Being able to make adjustments like this is really a battle between your eyes and your brain, it’s very difficult. How do we train this? By purposely swinging in the wrong location during batting practice so when you get in a game you can do the same and get the result that you want.

If I’m throwing BP there’s no way I can’t adjust the spin on the BP fastballs I’m throwing without changing my grip, if I could change the spin on my pitches without changing velocity then the type of training below wouldn’t be needed (currently the only way to adjust spin rate without changing spin direction or velocity is by using a Spinball Pitching Machine, I’ll have one someday).

So the easiest way to train for spin rate without a Spinball is to throw hitters pitches with the same velocity, spin rate and direction every time (or as close as possible) and have them swing in different locations on the baseball.   

Challenge yourself to hit the ball in different locations without changing the way that you swing. Try the below drill to see how good you are at aiming your swing in different spots?

How accurate can you be? Can you force yourself to miss-over the top of the ball with your most aggressive swing? If you can’t swing over the top of the ball or refuse to it’s going to be tough for you to adjust to pitchers that have high spin rates since the ball will travel above the path that your eye perceive.  

As long as your swing is designed to hit the ball far and you commit to making that swing every time in training you hitting a ground ball in training can actually be a good idea. Why? Because a ground ball that is hit with a positive attack angle (the vertical angle at which your bat approaches the ball) was hit above the midline of the ball.

So if you want to learn how to hit homers off pitchers with high spin rates and you don’t have a Spinball pitching machine or see high velocity/high spin rate pitching all the time it’s good practice to use your same swing and hit ground balls. Thus, in some ways, ground balls do turn into homers, as long as the swing you make is a good one when you hit the grounder. Learn to swing against where your eyes tell you to because when pitchers are really good your eyes will most likely mislead you. So the same swing that produces a ground ball in training could actually produce a home run because of the increased spin rate/hop in a game setting. 

Thanks for Reading,

Kurt Hewes – Founder of Ignite Baseball

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