A lot of pitchers have disappointed this season.
Matt Harvey, Dallas Keuchel, and Chris Archer are some of the headline names.
However, there have also been plenty of positive and unexpected performances.
Those names include the likes of Junior Guerra and Steven Wright. In this piece, I will look at a name that started with the likes of Guerra and Wright, but has disappointed like Archer, Keuchel, Harvey with recent performances.
That player is Aaron Nola. What was the key to both his good and bad performances this season? Which version should you expect in the second half? Let’s take a look.
Deep Dive on Aaron Nola
Looking back at the first half
Since Aaron Nola started the season on a tear, fantasy baseball writers have tried to figure out the secret to his success. Many settled on his ability to get called strikes, so when his mid-June swoon occurred, this immediately jumped to mind.
The theory went that because he relies on the called strike more than the average pitcher, if he stopped getting those calls his performance would suffer.
I tried to test that narrative in preparation for this article. Here are my findings.
Between May 31 and July 18, Nola has made eight starts. Five of them were “bad” and three of them were “good.” If you look at the box scores, it won’t be hard to figure out which is which. For the purposes of the rest of this article, I used a quality start as the cutoff between good and bad.
In his five bad starts, 21% of Nola’s pitches were called strikes (88/204). This percentage was almost identical to that in his good starts (59/269). In contrast, in his five bad starts, Nola got swinging strikes in 7.9% of the time (32/255). That number spiked to 11.5% his three good starts (31/178).
For reference, in the five bad starts, Nola had a 13.50 ERA. In his three good starts, his ERA was 1.00.
With that small sample, it seems as if swinging strikes are a key to Nola’s success.
However, studying the first part of the season leads to different conclusion. In his first 10 starts, he had seven good starts and three bad starts. In his good starts, 26.89% of his pitches were called strikes. Meanwhile, 22.38% his pitches were called strikes in his bad starts.
In regards to swinging strikes, in his good starts, 10.84% of his pitches were swinging strikes. Meanwhile, 12.99% of his pitches were swinging strikes in his bad starts.
Thus, we seem to have a failed experiment and no definitive answer as to the effect of his called vs. swinging strikes in regards to the likelihood of Nola posting a quality start or not.
However, that doesn’t leave us without an answer as to his change in performance. In June, Nola’s hard contact rate spiked to 35.1%. His walk rate went up to 8.2% after being 4.7% and 4.5% in April and May respectively. The hard contact rate allowed his BABIP to jump to .528 (!) for the month and left his strand rate about 13% below his season-long average.
Looking Forward to the Second Half
It’s difficult to say which Aaron Nola will show up in the second half. It was nice to see a strong start against Jose Fernandez on the 18th. That makes me optimistic for the second half. My expectations are a 3.50 ERA with eight to nine strikeouts per nine innings.
However, he had nearly two weeks off between starts, which immediately makes fatigue as a factor in his struggles jump to mind. Beware that if his fall from the top ranks of pitchers was due to fatigue, or even if they Phillies simply believe it was the cause, he may well end up with shorter outings or an innings limit at the end of the season.
That leaves Nola as a risk, but one that is worth investing in. In season long leagues his price won’t be prohibitive, but if he gets on a roll like the one he had in April and May he could carry your pitching staff in the second half of the season.