Should we panic about Aaron Nola’s first four games?

The start of the season has been fun for Phillies fans. The offense has been mostly a pleasure to watch, Bryce Harper has been as exciting an addition as we could have hoped, and the team has the third best record in the NL (only half a game out of “first”). There have been some ugly games, but for the most part, this is the start we were hoping for.

Except for Aaron Nola. The staff ace who signed a four-year extension over the off-season has been terrible. Based on fWAR, Nola is 151st out of 167 starting pitchers this season. The pitcher who is next on the list — Nick Pivetta — is now pitching in AAA. That’s how bad Nola has been.

So for Phillies fans, the big question right now is how much should we panic over Nola’s start? Is this a sign of a major problem? Or is it a blip, like many bad starts to the season? After all, four bad games in August are not as obvious because the rest of the season masks the stats. Four bad games at the start of the season, though, stick out because there’s nothing to help hide the stats.

And the stats are ugly. Here’s just a few of Nola’s stats for 2019 so far, with 2018’s season-long stats for comparison. (The stats used here are chosen because they make the analysis in the rest of this article more feasible.)

There’s no two ways about it. Nola has been terrible to start the season. Just pulling out one metric here, batters had a .570 OPS against him last year compared to a .901 so far this year. That’s bad.

But is this panic-worthy bad? There are many ways to answer that question, but one way is to look back at Nola’s 97 career starts to see whether he’s ever had a 4-game stretch like this before. And if he has, what’s happened afterwards.

There’s good news and bad news when you look at every one of Nola’s 4-game clusters over the course of his career. First, the good news. Nola went into the season a top-flight major league pitcher despite having twice had stretches in his career that were as bad as — and even worse than! — this current stretch. Why’s that good news? Because it means that Nola has overcome these troubles in the past to become the ace we think of him today. Which means, though there’s of course no guarantee, that he’s likely to be able to overcome these troubles now.

There’s even more good news! The second of these terrible stretches for Nola occurred from August 17 to September 2, 2017 (starts 53 through 56 of his career). Here’s how that stretch compares to this one:

The game scores were slightly worse, and the slugging percentage of opposing batters was much worse. The big difference though is that Nola had a much better K/BB rate during the 2017 stretch, a rate just slightly lower than his year-long 2018 rate of 3.9.

The good news about this 2017 stretch is that Nola emerged from it to be a dominant pitcher again for the rest of the year. In fact, his next four starts were classic Nola. Over those four games, he posted a 2.49 ERA, allowed 1.14 base runners per inning, hitters had a .623 OPS against him, he had a 4.5 K/BB rate, and an average game score of 62.5.

In other words, Nola immediately recovered from his awful 4 games to be the dominant starter that we know and love. The hope we have to hang our hats on now is that he does this again.

But there’s bad news too when we look back at Nola’s career. The bad news is that he was also terrible, in fact much much worse, from June 11 to June 26, 2016. For four games in a row, Nola failed to get out of the fourth inning, giving up a total of 25 runs (22 earned) in those games. The numbers are as ugly as can be:

Here’s where it gets depressing. After that June 26 game, Nola pitched pretty terribly in the next four games, giving up 14 runs in 20 innings, and then he was shut down for the season with a UCL sprain that landed him on the 60-day disabled list. He then returned for the start of the 2017 season, but only made three starts before being shut down for another month with a strained lower back.

This is what Phillies fans fear right now. Not that Nola has turned into a terrible pitcher, but rather that there’s an injury lurking beneath the surface. Looking to 2016’s stretch of terrible pitching bolsters that concern.

Right now, there’s no hint of injury being an issue. Nola is scheduled to take the mound tomorrow night in Colorado, where he has only one career start (2.57 ERA, .609 OPS against).

What he does tomorrow won’t necessarily answer the question, but it will give us one more data point on whether this stretch is going to be more like the blip of 2017 or the nightmare of 2016.