4:02pm: Seattle has announced the deal.
4:00pm: The Mariners have moved swiftly on a second trade of the day, adding outfielder Jarrod Dyson from the Royals in exchange for righty Nate Karns, according to Bob Dutton of the Tacoma News Tribune (via Twitter). The speedy Dyson will take the place in the Seattle outfield just vacated by Seth Smith, while Karns will presumably enter the rotation mix for Kansas City.
For Seattle, this swap plainly functions in concert with the Smith deal, which brought in starter Yovani Gallardo. Evidently, the M’s prefer the combination of the veteran Gallardo and Dyson to the team’s preexisting assets. GM Jerry Dipoto cited Dyson’s “elite level defense and base running” as the motivating factors for his addition (via Ryan Divish of the Seattle Times, on Twitter).
While the earlier swap involved a pair of short-term veterans (though Gallardo does come with an option), the Mariners sacrificed some control with this move. Dyson, 32, is entering his final year of team control, though he’s still plenty affordable with a projected $2.5MM arbitration salary. The 29-year-old Karns, meanwhile, is still controllable through 2020 as a 2+ service-class player.
Though Dyson, like Smith, hits from the left side, they are otherwise quite different players. Dyson isn’t quite as adept with the bat in hand as is Smith. He has never finished a year with even an average batting line. Last year, though, was his best yet in the majors, as he hit .278/.340/.388 over 337 plate appearances.
Unlike the lumbering Smith, Dyson earns his keep on the basepaths and in the field. On a rate basis, Dyson is perhaps the game’s most valuable overall baserunner. Despite just 1,091 plate appearances over the past four years, he has accumulated the sixth-highest total BsR score from Fangraphs (23.2); for reference, Billy Hamilton comfortably paces the league with 36.6 BsR, though he has taken nearly 50% more trips to the plate. Dyson is also a consistent threat to run, having tallied 176 total steals in his seven full or partial major-league seasons.
Dyson is equally impressive with the glove. In that same four-year span, he’s 13th in the game in total defensive value (by Fangraphs’ UZR-based measure). Again, that compares favorably to the game’s very best fielder, Andrelton Simmons, who has nearly hit the century mark in defensive runs since 2013 but has over twice Dyson’s trips to the plate. Though Leonys Martin, another left-handed hitter, could conceivably hold onto his job as the regular in center, Dyson is obviously capable of playing there as well. That’s not to say that Dyson can’t impact the game from a corner spot, if that’s where he ends up.
Still, it could end up being a hefty price to pay if Karns can harness his evident talent. Last year, he compiled only a 5.15 ERA over 94 1/3 innings, which he compiled over 15 starts and seven relief appearances. But even as he struggled with his command (4.3 BB/9) Karns managed to strike out more than a hitter per inning. And he was a highly productive, MLB starter as recently as 2015, when he gave the Rays 147 frames of 3.67 ERA ball with 8.9 K/9 against a more palatable 3.4 BB/9.