Revisiting the Marcus Stroman trade six months later

Six months (and two days) ago, the Blue Jays traded Marcus Stroman to the New York Mets, as the front office definitely turned the page on the 2015-16 playoff teams and put their stamp on the franchise. It was a controversial and highly charged move, with Stroman a proven frontline starter who embraced Toronto and would have presumably been open to longer term (fair market) extension that would have kept him as a building block for and bridge to the next contender.

Instead, the Blue Jays chose to cash in the last year and a half of their contractual control, presumably at the highest level it would be given his strong performance. There was a rationale to moving him to a contender for premium prospects, so it was surprising to see it ultimately be the Mets and a farm system that had been heavily emptied out the previous winter. With the benefit of the perspective of some time and reduced passion, I thought it would revisit this critical move.

Let’s start with the return, which for many at the time was underwhelming and disappointing. I actually found it reasonable at the time, familiar with Simeon Richardson-Woods from the 2018 draft and liking the combination of pure stuff and its demonstrated ability to play in pro ball. I was glad to see they were willing to target a higher upside, riskier/further away prospect as a centrepiece. He had a nice run to finish the season with Dunedin, but unfortunately there’s little other insight to add (by one day he missed pitching in Bradenton which would have been televised).

I actually ended up a little down on the package than initially because of the second part, as I conflated another lefthanded Mets first rounder who I had seen pitch in AA in David Peterson with Anthony Kay. I personally prefer Peterson to Kay, but broadly they are ranked as similarly valued so it’s not something that would fundamentally change one’s view of the trade.

That said, while I think it was a reasonable return, it was not an overwhelming one. That is, not the proverbial “offer you can’t refuse” even if you didn’t plan on moving Stroman or weren’t committed to it. Rather, it was a discretionary strategic decision by the front office, and a significant one at that for the medium term future of the franchise over the next five years, and then potentially 10. How it works out will be an important determinant of the Shapiro/Atkins legacy.

Assuming that an extension was possible, the critical question is thus would have made more sense to keep Stroman. It’s impossible to say what that would look like, on the back of two infamously soft winters for free agents, but also with a thin class of pitching set to be available in the 2020-2021 offseason. I’ll assume it would start at at least five years and $100-million, and perhaps that just covering the free agent years so something like six years and $115-million including the last control year in 2020.

There’s numerous factors that make me reticent to think that level of commitment would be the best course of action, beyond the fact that major guarantees to pitchers are inherently a very risky gambit. This is not to dump on Stroman, who’s a very good pitcher. Short of a true ace (pardon the pun), but an established frontline pitcher with 850 innings preventing runs 10% or so above average.

The first relates to the issues of Stroman and strikeouts that I investigated earlier this week:

The issue isn’t that Stroman’s strikeout rate is mediocre; he’s more than proven he can be an effective starter without piling up strikeouts. Rather, the issue is the trend(s). Stroman’s strikeout rate has trended slightly downward over time, though if 2018 is set aside for the shoulder issues, then it’s then it’s been quite stable.

But strikeouts have increased by about 10% since Stroman broke into the league (from about 20% to over 22%), so even if in absolute terms there’s no change, in relative terms Stroman has declined. That shows up in the trend of his K%+ (indexing it to league average), from 103 in 2014 to 93 in 2016, then 91 and 78 before stabilizing at 85 in 2019 at the time of the trade. It did bounce up to essentially league average (99) with the Mets, which I’ll touch in later.

So even in his prime years, there’s some evidence of decline in a core skill. Less significantly, his walk rate has also moved against him. Through 2016, Stroman’s 5.9% walk rate (76 BB%-) was very good, ranking roughly at the top quartile of qualified pitchers. Since then, it’s up to 7.6% (90 BB%-), merely average for qualified starters (who have better control, hence still being above average).

While these trends aren’t great, both of these are potentially small potatoes compared the next issue of concern. Stroman’s bread and butter has been to generate weak contact, mainly by piling up ground balls: from 2014-18, his 60% ground ball rate was almost 40% better than average (138 GB%+), tied with Dallas Keuchel at the top among pitchers with 500 innings.

What’s equally clear is that his ground ball ability IS his ability to generate weak contact. Statcast shows his exit velocity is about a 1 MPH worse than average, with an above average rate of hard hit balls (38.6% to 34.5%). When the ball was elevated, he gave up more home runs than league average (110 HR/FB+). This is not unusual for ground ball pitchers — it’s the nature of being a sinkerballer who lives at the bottom of the zone. Most of the contact is at a low launch angle, and even hard hit balls on the ground mostly turn into outs (and otherwise are singles or occasionally doubles; no big deal). But when the ball flattens out, batters tend to square it up.

So it was another point of concern for me that Stroman’s ground ball rate slipped some in 2019, down to 56% prior to the trade. That’s still elite, one of the best in baseball, but a significant step down from 62% the prior two seasons. His pitch mix suggests this isn’t merely a blip — in 2019 with the Jays, he was using his sinker a lot less, about 34% compared to 42% career, and leaning heavily on his slider (21% to 35%) with increased cutter usage

While it cannot be factored into any basis for trading him, Stroman’s finish to 2019 with the Mets is instructive to this point. As noted above, over 60 innings he increased his strikeout rate to 23% and around league average. But alarmingly I’d contend, his ground ball rate plunged further to 48%. If going forward he’s a guy with basically average strikeouts, basically average walks, and basically average contact, then he’s...basically a league starter. Curiously, his sinker usage returned to career norms in this stint, with more cutter usage instead of heavier slider usage. And yet, fewer ground balls.

For a number of reasons, xFIP is far from a definitive stat, but Stroman’s yearly progression tells a story: 3.17, 3.34, 3.41, 3.59, 3.94, 3.99. SIERA suggests an even more dire story: 3.18, 3.28, 3.62, 3.85, 4.04, 4.41. In fairness, that’s against a backdrop of a significant jump in offensive levels over the time period, so the jump isn’t as bad as the headline numbers indicate. Still, it represents significant slippage.

A third concern would be injuries. Even setting aside his 2015 ACL tear as a one-of fluke, there’s the shoulder issues that afflicted him in 2018, limiting him to 102.1 innings of significantly reduced effectiveness. This isn’t a red flag per se, it apparently wasn’t structural and he was effective in 2018. But shoulder injuries are no joke, and extreme ground ball pitchers have tended to disproportionately have their careers shortened by them (recall Brandon Webb). It’s definitely something that would worry me about a long guaranteed contract for Stroman.

And finally, there’s the elephant in the room, his height. There’s been a lot of unfounded nonsense on this subject over the years, and with little in the way of tangible evidence I’m hesitant to even bring it up. But anecdotally, it does seem there’s a case that shorter pitchers have not been as durable. Tim Lincecum was effectively done by 30, ditto Johnny Cueto. Tom Gordon didn’t start a game after age 30. I’m sure the Blue Jays did far more comprehensive analysis on this point, and perhaps it’s bunk or was another data point for moving him, but again it’s something that for me would be a flag.

Maybe Stroman makes these concerns look really stupid five years from now, and it is regrettable when franchise stalwarts are moved. But all that taken together, I see preferring to trade Stroman for what they did rather than extending him at what he would have reasonably commanded as at least a perfectly defensible position, if not outright the right decision.