Mike Soroka Has His Work Cut Out For Him

Here at Pitcher List, we’ve all been working tirelessly to unveil Pitcher List 5.0 for months now. Suffice it to say, I hadn’t had much time to do many player write-ups, and I’ve missed it deeply. Given that I’d already written up the Braves starting rotation, it worked out perfectly that, about a month ago, a Pitcher List colleague reached out to me to do a write-up on Mike Soroka. Despite posting a 2.79 ERA over 200.1 innings, he’s been met with a considerable amount of skepticism. The odds of him repeating his 2019 are slim, but there’s a reason Soroka was dominant too. He’s not your everyday pitcher.

I’ll admit that I’ve been one of his skeptics, and I know that Nick has had his doubts as well. There is a pretty simple set of reasons for our reluctance.

Of starters with 500 pitches in 2019, by percentile:

• xwOBAcon: 83rd
• K%: 31st
• BB%: 73rd
• SwStr%: 52nd
• CSW: 64th

He grades out well by batted-ball quality, as well as walks — the rest is relatively average (other than his strikeout percentage). It’s easy to assume that he has a strong walk percentage because of his command, but he has a 102 Command+. Rather than plus command (although that still has a chance to develop), it has more to do with the fact that Soroka allows a lot of balls to get put into play, rather than finishing at-bats with walks — this also pertains to his deficit in strikeouts. Of all starting pitchers, Soroka ranks in the 84th percentile with 72.8% of his balls being put into play, meaning — more than most pitchers — a significant amount of Soroka’s offerings end up in play.

Unless he makes a change, that alone is always going to limit Soroka. The good? A ball being put in play isn’t a walk. The bad? It’s also not a strikeout. And he doesn’t do a ton of that.

On one hand, that means fewer pitches per inning:

2019's pitches/IP leaderboard:

1. Soroka: 14.6
2. Ryu: 14.8
3. Greinke: 14.9
4. Kershaw: 15
5. Marquez: 15
6. Leake: 15.1
7. B Anderson: 15.1
8. K Hendricks: 15.2
9. Tanaka: 15.3
10. Verlander: 15.5
11. Bieber: 15.5

— Alex Fast (@AlexFast8) February 1, 2020

 

On the other hand, that means Soroka is entrusting his faith in his defense. Generally speaking, that isn’t a plan for success for many pitchers. Given that I wrote about Soroka’s teammate Luke Jackson suffering from these woes of poor batted-ball luck, perhaps he’s sunk after all. In terms of sustainability, we know that inducing swinging strikes is stickier year-to-year than contact management is. I noted above that Soroka ranks in the 83rd percentile in xwOBAcon, but he ranks in the 99th percentile in wOBAcon for starters. And so, by wOBAcon, Soroka was the best starting pitcher in baseball last year, but xwOBAcon isn’t as optimistic.

There are two ways to look at it. If you think it’s sustainable, then fantastic! The Braves have found themselves a contact management artist. If you’re like me, you’re a little more skeptical that this level of contact suppression can be sustained. I mean, really, I don’t find that point debatable. In filtering starters’ wOBAcon since 2015, you will find that Soroka is perched atop the list with a .318 wOBAcon. Filter by xwOBAcon, and you see Soroka fall to the 85th percentile. That’s still quite fantastic, and so it is certainly still reasonable that Soroka can still be elite in the contact suppression department. I’m going to offer two arguments.

 

The Precedent Argument

 

This argument is simple enough. There are several pitchers that Soroka is similar to who have made this work. You can pitch to contact, so long as you consistently hit your spots and have a few good ground ball pitches. Theoretically, if we can find some pitchers with a similar profile, we should be able to say with greater confidence that Soroka can make this approach work and be one of the best starting pitchers in the league.

He’s drawn several comparisons to Kyle Hendricks and Marcus Stroman as of late. Let’s compare them:

 

We can see that the most disparate number is wOBAcon, which I would argue matters the least in this table. The difference is that Soroka holds a (nondistinct) edge in swinging-strike percentage, and Hendricks is far superior to the other two in walk percentage because of his elite ability to command his pitches.

The differences, as I see it, fall outside this table. Soroka is more akin to Stroman as it pertains to getting hitters to put the ball on the ground, and they’re more similar in terms of command and repertoire, too. For now, then, it feels fair to say that Soroka is something resembling Stroman and Hendricks — just without the track record.

I think Soroka is legitimately skilled at suppressing hard contact. Of pitchers with 10 or more starts, Soroka ranked 11th in ground ball percentage. That’s mostly because of his sinker, which collects a large number of ground balls due to its heavy sink and arm-side run, but his slider and changeup get their share of ground balls too. The question, then, is how skilled is he at contact management?

 

The Miles Mikolas Argument

 

You wouldn’t think so by looking at his 4.16 ERA in 2019, but Miles Mikolas was brilliant in 2018. He celebrated a four-year MLB hiatus by coming back and posting a 2.83 ERA, 3.28 FIP, and 4.2 WAR. Of course, you’ll find that his supposed breakout (and 18.1% strikeout percentage) was artificially supported by a .279 BABIP, 0.72 HR/9, and .309 wOBAcon. At the time, many of us rationalized this to ourselves. Look no further than me — I bought into it!

Back then, I reasoned that, sure, Mikolas had a deflated .309 wOBAcon, but his .321 xwOBAcon was fantastic. Plus, with his command and sterling walk rate, perhaps he was the guy to be the exception to the rule. Maybe he deserved it.

As I have learned over the past year, wOBAcon and xwOBAcon have wide error bars — especially at the pitch type level — and so they are prone to a lot of statistical noise. In hindsight, we can see that Mikolas fooled us by overperforming via wOBAcon, but also xwOBAcon. Often, this comes by drastically overperforming on a pitch or two, but Mikolas saw vast overperformance with his four-seam fastball, sinker, and slider. We probably shouldn’t have believed any of it. Should we believe in it with Soroka?

Soroka’s pitch type wOBAcon and xwOBAcon, relative to their respective league averages:

 

I know this might be overwhelming, so focus we’ll on one aspect at a time. In comparing his wOBAcon to the league average wOBAcon for each of his pitch types, we can see that Soroka significantly outperformed the league averages with every pitch. Immediately, we’ve come across a red flag.

Next, we can compare his xwOBAcon to league average xwOBAcon. Again, we see that his four-seamer and changeup vastly outperformed the league average xwOBA. In particular, his four-seamer’s xwOBAcon doesn’t seem sustainable at all. This time, his sinker looks more mortal, yet still better than average. And then there’s his slider, which actually got beat up more than what is typical of a league average slider. Here is where we put it all together. What does this mean?

The hardest part is knowing where Soroka’s pitches are going to regress via xwOBAcon, because that’s essentially his “deserved” pitch performance. Some are easier than others, as it is all but certain this his four-seamer is going to regress. Not only is its wOBAcon lower than its xwOBAcon, but his four-seamer xwOBAcon is nearly 100 points below league average. There is absolutely no way he can sustain that. The same exact thing goes for his changeup. Its xwOBAcon should regress toward league average, and its wOBAcon should follow too, given that it is more than 100 points lower than league average.

Since I believe in his sinker and think his four-seamer and changeup are unlikely to continue to maintain this level of dominance, it’s going to come down to his slider. The other pitches, as I see it, are going to regress. That’s not a foregone conclusion, because this is baseball, but the odds that he is able to double down on his 2019 is unlikely. Luckily for Soroka, his slider is pretty good at drawing whiffs. In spite of his 34.7% O-Swing percentage, his 15.9% swinging-strike percentage is fairly strong, and so even as his slider’s wOBAcon inevitably regresses, he’s still got that to hang his hat on.

I, for one, am not going to be the one to stick my neck out for Soroka. I like him just fine, but at some point, we have to acknowledge that pitchers like Zack Greinke and Kyle Hendricks are absolute unicorns. For every one of them, we find ourselves with, like, thirty-two different versions of Mike Foltynewicz, Miles Mikolas, or Kyle Freeland. I will go as far as to say that I think Soroka is legit, and I think he can back up his strikeout, walk, and home run numbers (and so, I think his 2019 FIP is more or less justifiable) but I would also be very surprised to see him repeat that campaign in 2020.

Photo by David J. Griffin/Icon Sportswire | Adapted by Zach Ennis (@zachennis on Twitter and Instagram)