Grading the Mets’ Trevor May signing

After a couple quiet weeks, the Mets made their first major acquisition of the offseason, inking Trevor May to a two-year, $15.5 million deal. May, a 31-year old right hander, has spent the entirety of his major league career in Minnesota. Since transitioning to the bullpen full time in 2016, he’s been one of the better relievers in baseball, ranking in the top 15 in K% and K-BB% while posting a 2.89 ERA and a 3.45 FIP over the past three seasons.

May’s improvement since returning from Tommy John surgery in 2018 bears some deeper investigation. His fastball velocity has steadily increased, reaching a career high 96.66 MPH in 2020. He’s also added an additional two inches of rise and an an inch-and-a-half of run to the pitch thanks to improved spin efficiency. Meanwhile, May’s slider has evolved into a fusion of his old slider and curveball, leading to more vertical movement at a slightly lower velocity. Perhaps due to having more confidence in the pitch, May threw his new slurvy breaking ball at a career-high 32.25% clip in 2020, leaning into the “breaking ball revolution” sweeping across Major League Baseball.

The end results of these changes was a career high 39.6% whiff rate last season that ranked 11th in baseball among relievers. Unfortunately, the strikeouts were accompanied by a big spike in home runs thanks to career highs in LD% (29.4%), FB% (45.1%), and HR/FB (21.7%). Mix this all together and you get bottom line numbers that suggest May’s evolution hasn’t changed him much as a pitcher and, if anything, might have made him worse; his FIP and DRA- for the last three seasons are 3.08/3.73/3.62 and 67/81/81 respectively.

We are dealing with a very abbreviated season in 2020 of course, so how meaningful are any of these numbers? This line of thought leads to a more optimistic conclusion, as strikeout rate stabilizes much faster than HR%. That doesn’t totally abrogate concerns about May’s novel gopheritis, but it makes it much more possible to squint and see a special reliever—one who runs top-of-the-line strikeout and walk rates without also giving up a home run every other time he takes the mound. It’s worth noting that Mets pitching coach Jeremy Hefner worked with May in Minnesota. Perhaps his belief in the changes May has made to his arsenal over the past three seasons influenced this signing, which would be another cause for optimism.

On a macro scale, this move bears scrutiny as well. Evaluating relievers is often a fool’s errand due to the small sample sizes and noise inherent in their year-to-year performance, and there’s an argument that waiting out the market for the best value on a given tier of relievers is better than paying a premium to plant your flag early. Look no further than the previous paragraph or our evaluation of the Jeurys Familia trade two years ago for an example of how much uncertainty there is in any reliever valuation. Put mathematically, it’s difficult to assemble any amount of evidence that overwhelms the prior on relievers being extremely unpredictable year-to-year.

This argument on the philosophy of reliever valuation leads to two practical questions; did the Mets pay a premium to sign May early, and if they did, do the underlying data suggest he’s worth it? Answering the former isn’t possible until we see how the rest of the market plays out and what sort of contracts guys like Trevor Rosenthal and Blake Treinen sign. As for the second question, I don’t have a problem paying a slight ($1-$2 million) premium for May but wouldn’t argue with those that want to ding the grade because of it.

What we know at the moment is that May is a very solid second-tier reliever with a track record of late inning performance, potential upside beyond what he’s shown, and a fun off-the-field personality to boot—check out his Twitch if that’s your bag. His contract is reasonable and just about in line with estimates, and he fills an obvious hole on a Mets roster starved for pitching. Overall, it’s a very good first-addition for the 2020-21 offseason, earning this signing a B+*.

*Will be reevaluated at the end of the offseason to reflect how the market developed