Brandon Nimmo has been getting his share of attention in the trade rumor mill, though the Mets have made it clear he's a player they want to keep. They reportedly didn't want to deal the 24-year-old outfielder to get Andrew McCutchen, and now they seem equally reluctant to trade Nimmo for another Pirate, Josh Harrison.
McCutchen could have filled an important need for the Mets (since addressed with the signing of Jay Bruce), and Harrison would, too, at second base. But there are good reasons for the Mets to have an attachment to Nimmo, beyond "outfield depth." Statcast™ helps illustrate the potential the former first-round pick has to be an all-around contributor.
By his stat line, Nimmo performed strongly in 2017. He hit .260/.379/.418 with five homers in 215 plate appearances, good for a 117 wRC+, meaning he was 17 percent better offensively than league average. He had a high strikeout rate (27.9 percent) and maybe some batted-ball luck (.360 batting average on balls in play) -- but there are several key areas where Nimmo was particularly strong.
One is line-drive rate. Nimmo hit line drives on 30.8 percent of his batted balls last season, the highest of any regular Mets hitter and 25th highest of 387 MLB hitters with at least 100 balls in play. (For reference, that's one spot above Corey Seager's 30.7 percent. Jed Lowrie led MLB at 34.3 percent.) Line drives, of course, are the most favorable batted-ball type for a hitter -- since Statcast™ started tracking in 2015, MLB wOBA on line drives is .706, compared to .381 on fly balls, .228 on ground balls and .022 on popups.
Mets' highest line-drive rate, 2017
Min. 100 batted balls
1. Brandon Nimmo: 30.8%
2. T.J. Rivera: 29.7%
3. Michael Conforto: 28.2%
4. Lucas Duda: 27.9%
5. Amed Rosario: 25.9%

Another is plate discipline, where Nimmo excelled. Much of his offensive value stemmed from his 15.3-percent walk rate, which tied for 10th highest among players with 200-plus plate appearances in 2017. Nimmo had one of MLB's lowest chase rates -- he swung at just 13.3 percent of pitches Statcast™ tracked as outside the strike zone, third fewest of more than 400 hitters who got 250 or more out-of-zone pitches in '17. That ranked just ahead of the extremely disciplined Joey Votto, who had 134 walks to 84 strikeouts last year. Nimmo did in just a slice of a season what Votto does over full seasons year in and year out, but it's encouraging nonetheless.

We can actually break down Nimmo's plate discipline in even more detail. Statcast™ also groups pitches into one of three regions -- the interior of the strike zone, the edges (within one baseball's width of the borders of the zone) and the far exterior of the zone. Effectively, these are clear strikes, borderline pitches and clear balls.
The difference between Nimmo's swing rate at clear balls versus clear strikes was striking. When thrown a non-borderline ball, he offered just 5.1 percent of the time -- the lowest rate of 349 hitters who were thrown 250 or more of those pitches, and again just ahead of Votto, who was at 5.3 percent. (Votto's number is incredible in its own right; it was the lowest by any hitter in a full season since Statcast™'s introduction.) The MLB average chase rate on clear out-of-zone pitches was 18.9 percent, more than three times Nimmo's.
Lowest swing percentage on "clear balls," MLB hitters, 2017
Min. 250 non-borderline, out-of-zone pitches seen
1. Brandon Nimmo: 5.1%
2. Joey Votto: 5.3%
3. Alex Avila: 6.1%
4. Greg Garcia: 7.0%
5. Robbie Grossman: 7.5%
On the other hand, when thrown a pitch within the interior of the strike zone, Nimmo swung 71.6 percent of the time -- a 14-fold increase from "clear ball" to "clear strike." That was basically identical to the Major League average rate of 71.7 percent. Of 336 hitters who were thrown at least 250 clear strikes, Nimmo fell right around the midpoint.

For pitches on the edges of the zone, Nimmo's approach was to take. Borderline pitches are a toss-up -- when taken, they were called balls 53.5 percent of the time and strikes 46.5 percent of the time in 2017. Nimmo took 65.3 percent of Statcast-tracked edge pitches, third most of 379 hitters who saw at least 250 borderline pitches, more even than notably patient hitters like Matt Carpenter and Joe Mauer. Nimmo's results were in line with the rest of the Majors, slightly favoring him as the hitter. Nimmo got a called ball on 54.7 percent of borderline takes, with 45.3 percent called strikes -- although he also had 36 strikeouts on borderline pitches to 14 walks.
There's one more piece to tack into the equation: Nimmo's fielding. Nimmo's outfield defense graded well, going by Statcast™'s Outs Above Average metric, which uses a plus/minus system based on the catch probabilities of the batted balls hit an outfielder's way. Nimmo was worth two Outs Above Average in 2017, ranking in the top 25 percent of qualifying outfielders -- perfectly serviceable for a third of a season of defensive playing time. He even made a couple of the highest-difficulty plays, with one 5-Star catch and one 4-Star catch.

Nimmo also showed more than enough speed to handle the outfield. His average sprint speed was 28.5 feet per second, which was inside the top 15 percent of Major Leaguers, second fastest on the Mets behind Rosario's top-tier 29.7 ft/sec and much faster than the 27 ft/sec MLB average.
Highest average sprint speed, Mets players, 2017
MLB average = 27 ft/sec. 30+ ft/sec is elite

1. Amed Rosario: 29.7 ft/sec
   2. Brandon Nimmo: 28.5 ft/sec
   
2. Juan Lagares: 28.2 ft/sec
   T-4. Jose Reyes: 27.9 ft/sec
   T-4. Matt Reynolds: 27.9 ft/sec
   It's not to say that Nimmo will develop into a star. But he has the tools to be a valuable player for the Mets. There's justification for keeping him around.