The Mets have a really amazing pitcher named Jacob. He’s one of the best arms in the league, shutting opponents down with such regularity it’s become boring. He’s an imposing figure on the mound, standing 6 feet, 4 inches tall. And his last name isn’t deGrom.

Jacob Seth Lugo (yep) has been an excellent pitcher throughout his first few years on the Mets, but this season, has blossomed into one of the best in all of baseball.

His rise has been what you might call meteoric; his three years pitching at Centenery College in Louisiana yielded uneven results, as he finished with a career 5.31 college ERA on his way to barely eking his way into the 2011 MLB Draft. The Mets took a lot of pitchers in the draft that year. An awful lot – in more ways than one. The pitchers, for the most part, either never ended up pitching for New York, or were aggressively ineffective once they got there, despite the Mets investing picks in each of the first 5 rounds on them. By the value-encapsulating WAR, the first whopping 8 arms have been… uninspiring:

8 pitchers; 2.0 WAR for the Mets combined. It wasn’t until round 34 that the Mets found a real diamond in the rough, a player who’d more than double the contributions of his 8 priors:

Round Pitcher Career WAR for the Mets 1st Michael Fulmer 0.0 2nd Cory Mazzoni 0.0 3rd Logan Verrett -0.7 4th Tyler Pill 0.0 5th Jack Leathersich 0.1 13th Robert Gsellman 2.6 21st John Gant 0.0 28th Jharel Cotton 0.0 34th Seth Lugo 4.7

Once drafted, though, the road was still anything but easy for Lugo.

In 2012, he missed the entire season due to a condition called spondylolisthesis, which required spinal fusion surgery (not a great situation for a professional pitcher) and left him bedridden for 3 months. He then labored for 3 more years in the minors before finally making his debut for the Mets in 2016 at the age of 26. He had a 6.50 ERA in AAA.

However, once hitting the majors, he made an immediate mark. With Matt Harvey, Steven Matz, and Jacob deGrom all opting for season-ending surgery in 2016 (those were dark times), Lugo and his fellow draftmate Robert Gsellman were part of a “replaceMets” rotation that fueled New York to an incredibly unlikely run to the Wild Card game.

Despite his success starting for the Mets in 2016, Lugo’s role slowly began to change. In 2017, he pitched a total of 101.1 innings, starting 18 games. In 2018, he again pitched exactly 101.1 innings, but with only 5 starts. This season, he’s yet to start a game, and is just under 60 innings thus far, second behind Robert Gsellman among Mets relievers (whether that’s a mistake or not is another conversation).

All Lugo’s done across this period is improve. When charting his 81-game rolling FIP (a fielding-independent version of ERA), you can see a pitcher who’s gotten better and better just about every game – and the effect has been even more stark in 2019:

By WAR, he’s been the 14th-most valuable reliever in all of baseball this season, ahead of such names as Adam Ottavino, Kenley Jansen, Zack Britton, and more:

Though I do love WAR, sometimes I feel it isn’t necessarily the best advanced statistic with which to evaluate relief pitchers. After all, so much of what they do is shutting down high-leverage situations – leaving guys stranded on base, or locking down an important inning. What I like better is WPA (win probability added). You may have seen such “win probability” charts as these (I chose a totally random game of no significance):

In this game, for example, the leaders in WPA were Michael Conforto and Todd Frazier. When thinking back upon the game, those are pretty much the two names that come to mind as winning the Mets the game, no? That’s why I think WPA is so important to take into account in late-game high-leverage situations – which are the bread and butter of relievers like Lugo.

Let’s look at the top 15 WPA instead of WAR:

Lugo’s been even better by this measure – 8th in all of baseball.

It seems clear that Lugo’s made his way into the MLB bullpen elite. But how?

Even in 2016, many people in Statcast and advanced metrics circles knew who Lugo was because of one specific skill – his curveball. Lugo had the highest spin rate on his curveball of any pitch Statcast had ever tracked – a higher spin rate on a curveball will mean a sharper curve and a more difficult pitch to hit. The first full-season percentile tracking Statcast has for Lugo is 2017, and it’s clear he had one very strong strength:

Since then, his curveball has lost absolutely no juice. As a matter of fact, in 2019, Lugo ranks in the 100th percentile MLB-wide in curveball spin rate. Don’t take the numbers’ word for it – look at some of these vicious strikeout-inducing hooks, all from 2019:

Sheesh.

Sheeeesh.

Of course, Lugo’s curve was just as nasty in 2016 – so what’s changed to get his WPA to elite levels and his FIP in steady decline? Take a look at his updated Statcast profile in 2019:

You might notice a whole lot more red here than we saw earlier – an elite strikeout percentage (93rd percentile up from 34th in 2017) and better hard hit percentage (62nd percentile up from 26th) improving with his peripherals across the board. I would argue this all stems from one source – his improved fastball.

A great curveball is of course even more deadly when it has a great fastball to play off of, and vice versa. While Lugo’s fastball hovered between 92 and 93 MPH in his rookie season (31st percentile leaguewide), it now averages between 94 and 95 (73rd percentile). Those couple miles per hour can make a world of difference in keeping hitters off balance and fearing more than one pitch. Lugo knows it, too: take a look at how the percent of time he throws his fastball (red line) has trended up with his average fastball velocity (blue line):

Now he can do this on 1-2 counts to super phemons like Ronald Acuña Jr:

Even when they are able to put the ball in play, hitters have had a really tough time getting good contact against Lugo. Here’s another chart of blue fastball velocity, but now with the red line representing the percentage of balls in play classified as line drives:

You can see a pretty clear inverse relationship there – the more nasty Lugo’s fastball has become, the more difficult it’s been for hitters make good contact.

With so much talk about the Mets’ bullpen being a disappointment this season, more leagewide (and Mets fan-wide) attention deserves to be on Lugo, who’s only getting better and whom the Mets have under contract until 2023. Lugo’s success is one of the great stories in baseball – a 34th-round pick from a small school who battled injuries and a long, uneven career in the minors on his way to becoming arguably one of the 10 best relievers in baseball, a guy who his manager can trust to close out both the last two innings of a crucial playoff-level battle like Saturday night’s win against the Nationals:

Enjoy Seth Lugo, Mets fans. Just make sure you appreciate him.