Left Field: 2.2 fWAR - 16th
This one might surprise people. The Mariners saw Kelenic play about half this seasons games in LF, but then they still had 6 other players register double-digit appearances out there. Canzone (26), Marlowe (24), Pollock (23), Moore (22), Haggerty (16), Trammell (11). To get league-average play with that many rotating bodies is still impressive. Especially when you realize it wasn't the lowest mark in the Mariners outfield.
Center Field: 5.9 fWAR - 2nd
It's so much fun having Julio in Center. He's getting better as a defender as he learns the position, pairing his top-of-the-line foot speed with a strong arm. We all saw what he can do when he gets hot, and there's a little part of me that wonders what would happen if he could put it together for a whole year... or at least for half a season while still hitting .265 the other half of the year.
Right Field: 1.7 fWAR - 22nd
This was pretty much all Teo, with Kelenic filling in for a while and playing some really good defense out there. When Teo is on, it's fun and a massive help to the offense. When he isn't it's hard to watch. Whether or not the team gets him back on the Qualifying Offer, or even offers it to him in the first place will be something to watch this offseason.
Designated Hitter: -0.1 fWAR - 22nd
Mike Ford "saved" this position for the Mariners, or else it would've been one of the worst ones in all of baseball. He didn't hit for a very good average, but a lot of walks and homers helped give a bit of spark to the second worst first half position for the Mariners. Fitting into the role of a True-Outcome player quite nicely, Ford at least made pitchers be wary when he was at the plate, and earned a shot at taking the role next year as well.