Nola’s Other Pitch
Aaron Nola‘s curveball has received a lot of attention this year, and rightly so. Nola has seemingly ridden an increased use of the pitch to raise his profile from solid starter to hearing whispers of “ace” just a month into the season. His curveball is undeniably excellent, possibly the best in the baseball, and now he’s throwing it more often without any decrease in effectiveness.
It was a simple adjustment, and one that has been well documented. But while the curveball has gotten all the attention, it’s really only half the story behind Nola’s rise this year. The other half, the one where he has made the bigger adjustment, is the two seam fastball.
Nola has increased the use of his two seamer in almost identical fashion to his curve. The pitch accounted for a little less than a quarter of all his pitches in 2015. This year, he’s throwing it over a third of the time. And when batters have put the pitch in play, it’s being hit on the ground two out of three times. Ground balls can’t leave the ballpark, and they rarely turn into extra bases, so the benefit of throwing the pitch is obvious.
The caveat with the two seam fastball is that it isn’t much of a swing and miss offering. But Nola has been able to mitigate the lack of whiffs with an increase in called strikes. The increase hasn’t been slight, either. You can see the difference in the year to year outcomes of his two seamer against right handed batters.
Nola is hitting the strike zone at the same rate, but getting significantly fewer swings at the pitch. And it’s not dumb luck that hitters are suddenly laying off his fastball. Nola has made a distinct adjustment in his location of the pitch
In 2015, Nola was throwing his two seamer down and in to right handed hitters. This year, he’s living on the outside corner. Because Nola gets almost 11 inches of arm-side run on the two seamer, he has to throw the pitch toward the left hand batter’s box in order to catch the outer part of the plate. You can understand how this would make it difficult for a right handed hitter to commit to swinging at the pitch. The result has been a lot of called strikes and perplexed looks from opposing hitters.
But what about left handed batters?
Nola is not only throwing more two seamers in the strike zone, he’s benefiting from more called and swinging strikes on the pitch. And like he’s done with right handed batters, Nola has changed his pitch location to lefties as well.
The difference isn’t as dramatic, but it’s still distinct. Nola is keeping to the outside edge, but he’s noticeably up in the zone from last year. Aside from being in the zone more often, there’s not an obvious answer as to why he’s getting the better results. My speculation is that by staying up in the zone with the two seamer, it’s hiding the curveball better, or maybe I should say the curveball is hiding the two seamer. If the initial trajectory of the two pitches is similar, it would make it difficult for the hitter to distinguish one pitch from the other, leading to late swings and bats left on shoulders. Whatever the reasoning, it’s given Nola a respectable fastball against opposite handed hitters.
By pitching to the corners of the plate and staying off the bottom edge of the zone, Nola has increased his rate of strikes on the two seamer by an incredible 76%, while still inducing grounders on two thirds of balls put in play. The improvement in the pitch, coming mostly on the back of the called strikes, has propelled Nola to the lead among all qualified starters in total strike rate, sitting three percentage points ahead of one Clayton Kershaw. So while Aaron Nola may be turning heads with the best curveball in baseball, don’t sleep on the two seam fastball, lest you get caught looking at strike three.