Comparing the Reliability of Steven Matz to Kevin Gausman, Robbie Ray, and Marcus Stroman

The St. Louis Cardinals signed Steven Matz to a four year deal last week just before Thanksgiving. While it’s still possible they’ll sign another starting pitcher, the likely target will be more of the swingman variety if it’s not already a role for someone currently on the roster. Derrick Goold said as much in his recent article about the Matz signing:

Matz is the starter they sought to add as the fifth and final member of the rotation, their interest shifting to identifying a swingman such as righthander Jake Woodford who can shift between starter and relief roles.

Right around the same time the Cardinals were introducing Matz to the media, free agent pitchers were flying off the shelves. Max Scherzer (Mets), Robbie Ray (Mariners), Kevin Gausman (Blue Jays), Jon Gray (Rangers), Alex Cobb (Giants), and Corey Kluber (Rays) all signed. Marcus Stroman signed with the Cubs just before the lockout began. By the time the smoke cleared, it left Carlos Rodon and Clayton Kershaw at the top of the starting pitching market, with a step down to less appealing options. There’s not much left in the starting pitching market by way of certainty.

That same day- Monday- Eno Sarris posted a great article at The Athletic in which he asked “Which free agent starter is the best long-term bet- Kevin Gausman, Robbie Ray, or Marcus Stroman?” It’s a great question. All three are 30 years old, all three are members of the top end of the pitching market, and- unlike Scherzer and Kershaw- are in their prime. Unlike Carlos Rodon, they’ve been durable. There are a lot of similarities.

Sarris understandably didn’t include Matz in his article, as Matz isn’t near the same class of effectiveness as the trio. That said, Matz is also 30, also in his prime, and has been as durable or even more than the trio since 2018. Sorting purely by games started in those four seasons, Ray has 100, Matz has 95, Gausman has 91, and Stroman has 84. Admittedly, Stroman mostly opted out of 2020, but the point remains. The others have nothing on Matz with regards to taking their turn in the rotation.

I don’t mean to rip off the article too much. You really should go read it. Here’s what Sarris used to determine the best long-term bet:

• K-BB%
  Strikeouts and walks are sticky from year to year. It’s what pitchers have the most control over. If a pitcher has a good K/BB ratio, it’s likely to continue.
• Stuff (Stuff+)
  Stuff+ is pretty sticky year to year. If you’re unfamiliar with it (it isn’t really publicly available), here’s what Sarris says: “Stuff+ is calculated based on only the physical properties of a pitcher’s arsenal — spin rate, spin axis, vertical movement, horizontal movement, release point, extension”
• Command (Location+)
  It’s not as repeatable from year to year, but does get more repeatable once you take out the bottom extreme. Also, obviously command is very important, even if it’s harder to repeat than velo, spin, and pitch shape.
• Number of Pitches
  I won’t get into the logic (read the article!) but the gist is that pitchers with deeper repertoires age better, as they have alternatives to rely upon as their fastball declines.
• Health/Injury History
  The best predictor of future injury is past injury. And fewer pitches thrown is better per Russell Carleton, since every pitch thrown leads to fatigue and worse results.

I’m not going to give you his conclusions for these three pitchers specifically- you’ll have to read the article for that. But this should give you an idea of the thought process.

K-BB%

Gausman and Ray have a clear edge in K-BB%, while Matz and Stroman’s K-BB% are interchangeable. Matz even has a slight edge if we look at the three year data. As Sarris points out in the article, though, we can also see how these pitchers have done with balls in play. Getting groundballs specifically is one of the most reliable skills as a pitcher ages. That’s where Stroman gets himself back in the conversation. Matz has been fine as a groundball pitcher- about upper third league-wide- but not as extreme as Stroman. It has led to HR rates for Matz that are more on par with Ray and Gausman- flyball pitchers.

Stuff+ and Location+

Sarris looked at both 2020 and 2021. I only have access to 2021. Here’s how our quartet fares. 100 is average- these are plus stats, after all. If it helps to give perspective, looking at pitchers with 1000+ pitches, Giovanny Gallegos comes in 30th (of 263) in Stuff+ at 112.4. J.A. Happ was 4th worst at 86.1. Alex Reyes’ Location+ was 9th worst (93.6) and Adam Wainwright was 45th best (104).

Here’s Stroman differentiating himself again. The Sarris article identifies their 2020 numbers, which shows Ray having taken a massive jump in command (location+) this season and a small jump in stuff+. That might help explain the middling Stuff/Location numbers but improved results. Whatever the case, Matz lags a bit behind the trio in location+ and bests only Ray in stuff. His stuff was 142nd of 263 and his location was 143rd. He was almost exactly average in both categories.

Number of Pitches in Repertoire

For Sarris to count a pitch, it had to be used 10% of the time or more, but had the caveat that it had to be effective by both Location+ and Pitching+ (a combination of Stuff+ and Location+). He had access to pitch-by-pitch data. Other than usage, I have no such access, so the Pitching+ and Location+ designations aren’t here.

Ray is a fastballl/slider guy, with just those pitches over 10% usage. Gausman is a fastball/split-finger guy and also has just two over 10%. In both cases, they’re very good pitches, but they’re the overwhelming majority of their arsenal. Stroman registers four pitches over 10% usage.

Matz has three- sinker, change-up, curveball- and his slider just misses the cut at 8.1%. I don’t have individual pitch Location+ and Pitching+, but we can look at FanGraphs’ Pitch Value metric. His slider was one of the least valuable in baseball among starters, as was his curveball. His change-up was quite effective and his sinker was roughly average. While he has three at 10% or more, he really only has two that were effective. He can use the others, to be sure, but it’s not quite the safeguard against velo decline that you want out of a deep repertoire.

Health/Injury History

We can look at Baseball Prospectus player pages to see what’s important. We’ll go back to 2016.

• Ray missed 58 days with an oblique strain in 2018, which is not that bad considering it’s the only non-fluky injury he had (he hurt his elbow in a home accident last spring).
• Gausman missed 11 days with tendonitis in 2019 and 31 days (some of which were in spring training) with a right shoulder strain in 2016.
• Stroman missed 45 days with right shoulder fatigue in 2018.
• Matz missed 14 days with left shoulder discomfort in 2020, 13 days in 2019 with a radial nerve issue, 15 days with a forearm strain in 2018, 45 days with an ulnar nerve issue in 2017, 72 days with a flexor strain in 2017, 49 days with a shoulder strain in 2016, and two shorter stints totaling 15 days with shoulder tightness and soreness earlier in 2016.

Matz has a relatively clean recent history- 42 days since 2018- but it gets nastier if you go further back. Unlike Ray and Stroman, Matz has had multiple shorter bouts instead of one big one. And while Matz’s recent history is pretty good, Gausman’s is even better.

The good news for Matz here is that he’s thrown considerably fewer pitches throughout his career than all four- about 4,000 less than Stroman and up to 7,000 less than Gausman. But that’s because of the injuries. When we look since 2018, he’s thrown many more than Stroman, right in line with Gausman, and quite a bit less than Ray.

It’s no surprise that the three big names fare better than Matz in these categories. I know that’s a big DUH- you’re probably wondering why I bothered with this exercise. Ultimately, it was to see how much of a gap there was and whether or not there was some reliabilty hidden in Matz that wasn’t apparent. (Early Cuyler voice) There were not.

Matz’s groundball stuff helps, as does his clean-ish recent injury history. His pitch totals aren’t so alarming that they’re troubling. Having three pitches that he uses with frequency and two of them reliable is also helpful. It’s reassuring in some perverse way that his Stuff+ is in line with Ray, even if both are below average. His Stuff+ and Location+ are average- again, below the trio, but decidedly better than Carlos Martinez, J.A. Happ, and Jon Lester. Clearly an upgrade even if not the one folks wanted (*cough*STROMAN*cough).

Gausman cost $110M, Ray cost $115M (each for an additional year), and Stroman got $23.67M AAV ($25M guaranteed for two years plus an option for a third, for a total of $71M). Given that Matz cost $44M in that context, the dollars in this contract make perfect sense.

There’s a reliability gap between Matz and the others, plus a gap in projected performance, but is it worth 2.5 times the cash outlay? That’s not a rhetorical question at all. Frequently the higher ceiling and a little more reliability is worth the extra cash. From the Cardinals standpoint, I think it was worth it for Stroman but understand some apprehension about Gausman and Ray compared to the Matz deal.

Or as the Cardinals Off Day folks- the former VEB Bens- so brilliantly put it on Twitter at the time of the deal: