What should Lance McCullers do with his curveball in 2018?

LOS ANGELES, CA - NOVEMBER 01: Lance McCullers Jr.
LOS ANGELES, CA - NOVEMBER 01: Lance McCullers Jr. /

Astros’ pitcher Lance McCullers’ upcoming 2018 season may have great bearing on his major league career.

In Game 7 of the ALCS, Lance McCullers threw 24 straight curveballs for the Astros. Yes, the Yankees saw 24 pitches in a row that were curveballs. 24 straight! I just can’t get over that even today.

We all know the outcome of that game, though. And while it may sound blasphemous, the result doesn’t matter in this particular instance. The question I would like to poise is what McCullers should do about his curveball next season?

By the numbers, McCullers had a higher curveball usage this year than he did in 2016. Brooks Baseball shows that McCullers threw his curveball 49.42% of the time in the 2017 season. By comparison, McCullers threw his curveball 48.54% of the time the season before. Of course, both percentages eclipse his 35.76% usage of the pitch back in 2015. In terms of actual results — .191 batting average against in 2017 — McCullers’ best pitch has been the curveball. Historically, his best has been his curveball in terms of batting average against.

On the flip side, McCullers has missed significant time the past two seasons. Part of that was due to a back injury earlier this year. But there is a history of elbow issues that has proven to be rather troublesome. That, unfortunately, was the concern attached to McCullers as he advanced quickly in the minors and as he made his major league debut. And what is one particular pitch that has been linked to elbow or shoulder issues, rightfully or not, amongst pitchers? That’s right; a curveball.

However, the question I would like to poise is this: should McCullers lean more or less on his curveball?

I desire to be careful on how I approach this subject as I am not certain that McCullers’ curveball is the culprit. There are multiple ways an arm can fail.

At the same time, I want to defend McCullers’ curveball. It’s an awesome pitch. For example, Fangraphs assigns pitch values, otherwise known as pitch type linear weights, for every pitcher and the type of pitches they’ve thrown. It’s a nifty tool to see how effective a player has performed in relation to certain pitches. And McCullers’ 36.7 wCB pitch value for his curveball comes in second to only Corey Kluber over the past two seasons amongst pitchers who have thrown at least 150 innings.

Now, we must discuss the reputation curveballs in general have acquired in relation to arm injuries.

The curveball, if you will, has long been viewed as a double-edge sword when related to arm health.

I must state, though, that I am no expert on pitching mechanics or biomechanics. Or anything medical for that matter. I am an accountant by trade. So, please don’t take stock on any medical speculation that may come courtesy of my thoughts, fingers and keyboard. Unless you see a qualified name along with a quote, then take what I say with a grain of salt. Or two. Listen to the actual experts. I’m just speculating.

One article that caught my attention on the subject was authored by Bill Pennington of The New York Times published back in 2012. The piece is called, “Young Arms and Curveballs: A Scientific Twist”, and it examines different studies and opinions ranging from USA Baseball to Dr. James Andrews in terms of youth baseball, arm health and curveballs. I recommend you read it for yourself when given an opportunity.

There are a few notable quotes in this piece, like this one from Glenn Fleisig of the American Sports Medicine Institute.

"“Science is banging heads with intuition and gut instinct,” said Glenn Fleisig, the research director of the American Sports Medicine Institute, who has conducted studies on breaking balls and young arms since 1996. “For years, we told people that curveballs were bad. Then we set out to prove it. We did not prove curveballs are safe, but we could not prove they were dangerous.”"

And this quote from Dr. Andrews, the renowned orthopedic surgeon, in regards to young arms. Hint: mechanics are key.

"“What we found out in the lab is true,” Andrews said. “For pitchers with proper mechanics, the force of throwing a curveball is no greater than for a fastball. But that’s not what happens in reality on the baseball field. Many kids don’t have proper mechanics or enough neuromuscular control, or they are fatigued when throwing curveballs. Things break down."

Pennington later noted that “one aspect of the curveball debate” that each individual involved in these studies agreed upon was “throwing too many pitches of any type is the biggest danger.”

Another, more recent article by Ian McHahan of Sports Illustrated  explored the subject of Tommy John surgery and if fastballs or curveballs are a primary cause. Hint: the curveball may not be the culprit we have been led to believe throughout the years.

A couple of studies are mentioned in the article by McHahan. In particular, a study by Dr. Andrews and Glenn Fleisig “showed pitch type made no difference in shoulder and elbow stress.” One interesting aspect of the article was about the torque of a fastball and curveball.

"“The relationship of torque for fastballs and curveballs is the same for adults and kids, so this does not support the theory that curveballs are more stressful for kids and less so for adults,” says Fleisig."

The root issue likely lies elsewhere, which is noted again by Fleisig.

"But if the type of pitch doesn’t make a difference, why has there been a spike in elbow injuries? Researchers like Fleisig believe that demonizing curveballs or fastballs ignores the more likely risk factors—fatigue and overuse."

To me, it appears that pitch type matters less in terms of arm injuries. “Fatigue and overuse” stated by Fleisig is a believable root cause.

However, I encourage you, the reader, to perform your own research as well. Read these entire articles to fully grasp their respective points. Review different sources. These two articles just happened to stand out in my opinion.

This now leads us to back to McCullers and his curveball.

Like I stated earlier, the right-handed pitcher threw a curveball in nearly half of his total pitches the past two seasons. That’s a lot. Out of all starting pitchers who have thrown at least 150 innings in the past two seasons combined, McCullers led baseball in curveball usage at 48.2% per Fangraphs. Rich Hill comes in second with a 39.7% curveball usage.

There is a reason why McCullers throws his curveball often: it is quite effective. It is simply McCullers’ best pitch in terms of the results. Each season McCullers has pitched in the majors, he has held opponents to a sub-.200 batting average against the pitch per Brooks Baseball. There was a notable batting average increase in 2017 of 0.054 compared to the season before. It will be something to watch next year to see if this batting average against the curveball decreases back to a similar level in 2015 and 2016.

Now, does the curveball usage correlate with McCullers’ injury issues the past two seasons? Maybe? Maybe not? I can’t state an answer as anything definite. I simply don’t know. There possibly could be a durability issue that is not constrained to one pitch for McCullers. After all, the most innings the 24-year old has thrown in a single season was 157.2 innings in 2015, which included his short stint in the minors that season. His inning total in 2017? 126.2 innings. And McCullers only threw 89 innings in 2016. The durability issue appears to lie beyond the curveball. Analysis of his pitching mechanics from more qualified individuals than myself would also shed light on the topic.

Based on the surface level analysis, McCullers could, in theory, use more of his curveball. It is his best pitch. We witnessed how good it could be against the Yankees in Game 7 of the ALCS. 24 straight curveballs! At a certain point, the New York hitters had to know what was coming. But they still couldn’t do anything with it.

Would an increased curveball usage lead to worse durability?


The history of McCullers throwing more curveballs the past two years have coincided with significant time on the disabled list. It isn’t outlandish to speculate that the curveball and the mechanics involved play a part.

Is it the sole cause?

Probably not.

Each arm is different in some way though, and the lack of durability may be more related to overall mechanics than an actual pitch. McCullers knows his arm and mechanics better than anyone else. I assume the same about the Astros. Again, I’m not qualified to give such opinions. I’m just speculating.

Next: Would you like a Christian Yelich with that?

Anytime you throw a small, white orb of leather and red stitches with any effort, the risk of injury is there. Risk is involved in everything. McCullers may want to throw his curveball more. It’s a very good pitch. We have witnessed as such in the past. The unknown factor is the effect it will have on his durability, which has been hampered the past two seasons. And the durability this season may help determine his long-term viability in the starting rotation.

**Statistics and information courtesy of Fangraphs and Brooks Baseball**