Marcus Stroman’s Improved Strikeout Rate

Straight from my basement bunker to yours, our first “Corona” post (as a philosopher once said: “You can have any virus you want… as long as it’s a Corona.”) is here! And we’re talking about… Marcus Stroman‘s strikeout rate? Well, yeah. As we enter this elongated (heh) period of nothing going on, what better way to proceed than focusing even more on information we already have. And what does that exactly mean in this context? Well, in terms of Marcus Stroman, there seems to be consensus that he might be alright this upcoming season (currently Razzball ranks him just above Julio Urias as the 43rd overall pitcher as of this writing, and is generally in the top-100 no matter which platform you choose). Whether you consider him a sleeper, a buy-low, or a player with expanded potential (why not all three!), this post will act as confirmation bias. Yes, I only offer the best bias. For those who are a bit more bullish (as the stock market shows, you should never go bear), this post is made for you. Think of it this way: Everyone knows Stroman did better the second-half. What this post presupposes is… maybe it can continue?

“Stroman’s K/9 went from 7.0 to 8.8 from the 1st half to the 2nd half and had a 3.28 ERA with a miserable BABIP (.332). Of course, he’s prone to some BABIP bad luck and iffy defense because he has a top five ground ball rate in the majors. His Ks only on the Mets were 9, recording 60 Ks in 59 2/3 IP. If Stroman holds these improvements to his K rates, and he’s gonna go from a ‘just okay’ fantasy number four to a number two, bordering on an ace. Dare I call him, Black Greinke.” – Grey.

I don’t quote Grey just to read what’s right, I also quote Grey so I can read his sweet nothings in my own voice. Look, it’s not sexual if you do it in your own voice! But why is Grey right? Because he always is? That’s it folks, we’re done here, let’s wrap it up.

Diving into the numbers, there’s a bit more to the story of Stroman just changing teams and magically improving his strikeout rate. And that story is the magic. Check out his first half pitches and how they faired in terms of ground ball rate and swinging strike rate:

As you can see, for the first half of the season, his fastball, slider, and cutter were used the most, and in that order. By far, his slider gained the most swinging strikes, with his fastball keeping the ball in the dirt at a strong clip. And now let’s take a look at the same table, but for the second half of the season and see what changed (spoiler alert!: bold…):

Interestingly enough, his fastball GB% lowered substantially, but was still generating swinging strikes near the same clip. The biggest change that sticks out is his cutter, both in terms of usage and effectiveness.

While this change looks to have started before switching to the NL, there’s obviously a strong case to be made here that whether through coaching, results, or both, Marcus Stroman utilized his cutter more, and with strong results. And while the potentially porous Mets defense might affect Stroman (his hit rate went from 8.5 to 9.8, with his BABIP rising .293 to .337 after the trade) most of his direct value is from an above average K/9 and a now three-season improvement with his HR/FB rate (from 17.8% in 2017, 13.6% in 2018, and just 12.6% last season).

I actually see him more as a Black Keuchel than a Black Grienke, I think we both agree that any follow sentence will probably be more racist. Regardless, there are a lot of reasons to buy-in on Stroman, and now there’s a lot of evidence to suggest that those reasons are real.

Jay is a longtime Razzball everything who consumes an egregious amount of Makers Mark as a vehicle to gain wisdom and augment his natural glow. Living in the D.C. area, he also likes spending time visiting the local parks and feeding lettuce to any turtles he encounters, including Mitch McConnell. You can follow him @jaywrong, or read his rarely (like never) updated blog Desultory Thoughts of a Longfellow.