Written by: Carlos Marcano (@camarcano)
Follow us on Twitter! @Prospects365
Sandy Koufax, Bert Blyleven, Satchel Page, Tom Glavine, Barry Zito, Clayton Kershaw: all of them amazing pitchers with a big common thing: they own some of the best curveballs in the history of the game.
We are used to seeing Kershaw’s 12-to-6 beautiful ‘Cooperstown’ curveball, like this one, in action:
That was Kershaw’s 2500 career strikeout a little more than a month ago. Nick Ahmed was the victim, of course, of a great curveball.
Or this one, handling the upper portion of the zone fearlessly:
By the way, this is the exact moment when Christian Yelich realized he was dead:
For lots of baseball fans in this generation, the C in Clayton stands for ‘curveball’.
So… Why doesn’t Clayton Kershaw use his curveball more?
According to Baseball Savant, Kershaw’s pitch usage since 2015 during regular season games looks like this:
His average use of the curveball since 2015 is 16.6% with a wOBA of just .171, ranking 3rd among pitchers with at least 1000 curveballs thrown during that span. This regular season the usage was 18.8%, which is the highest in his career. Opposing hitters posted a .228 wOBA against the pitch.
So, again, why doesn’t Kershaw employ his vicious hook more often? Well, as usual in baseball, there is not a simple evident answer to this.
Pattern logic leads to the belief that if you do something successfully, it means you should repeatedly do that to be successful all the time; the problem with that logic in pitching is that you have to account for an opposing hitter’s ability to adapt to those patterns: if batters only see curveballs, they will surely adjust before depositing their fair share of the pitch in the outfield bleachers.
That’s why pitchers know (or should know) they can’t use curveballs—or any pitch—in every count or in all counts. To illustrate this, let’s look at the wOBA leaders since 2015 on any two strikes counts while throwing a curveball (min. 5000 pitches, 200 CB):
Those are pretty nice numbers; Kershaw is a solid 12th with a 0.146 wOBA. The only pitchers who meet these qualifiers with a wOBA north of .300 are Julio Teheran and Clay Buchholz with .318 and .309 respectively.
Now, let’s check the results for the same qualifiers but in any favorable count for the pitcher (ahead):
Among the 109 qualifying pitchers in this situation, only 4 had a wOBA of more than .300. Again, Kershaw is in a great position with a .153 wOBA.
We can quickly form a general hypothesis using this data: plus counts or two strike counts appear to be an opportune time to utilize a good curveball.
Now, what happens when the pitchers got behind in the count? Let’s check it out:
That’s an abysmal difference; remember, in the previous charts only a handful of pitchers allowed a wOBA higher than .300; this time, only a handful of players allowed less than .300 and from there, wOBA simply skyrockets.
Now let’s be clear, the qualifiers are skewing the results because the chart is showing pitchers with a minimum of 200 CB thrown in that specific situation (pitcher behind in the count) so that includes pitchers who continued throwing curveballs despite enjoying very little success when doing so, which is one hell of a recipe for disaster.
In that regard, Kershaw knows better: during that same span, he only threw 28 curveballs when falling behind in the count. As you might expect, opposing hitters totaled a .501 wOBA in those opportunities.
One of the main differences between good and extraordinary? Doing what you’re good at in the right moment. It’s examples like the one given above that affirm why Kershaw has been one of baseball’s most extraordinary pitchers throughout the past decade.
Follow P365 MLB Analyst Carlos Marcano on Twitter! @camarcano
Follow us on Twitter! @Prospects365
All statistics from Stathead, Baseball Savant and Fangraphs.
Featured image courtesy of photographer Mary Altaffer and the Associated Press