SF-NYM: A position-by-position Wild Card look

The Mets and Giants have combined to represent the National League in the World Series in four of the past six seasons, so that alone makes today's NL Wild Card Game (8 p.m. ET/ESPN) fascinating.
Of course, it's been an odd season for both teams. San Francisco had the best record in baseball in the first half, then had the fourth-fewest wins in baseball in the second half. Meanwhile, the Mets managed a late surge to the playoffs despite being crushed by injuries; Matt Harvey, Jacob deGrom, Steven Matz, David Wright, Wilmer Flores and Neil Walker are all out for the year, to say nothing of those playing at less than 100 percent like Juan Lagares and Lucas Duda.
:: NL Wild Card: Giants vs. Mets coverage ::
Above all, Madison Bumgarner against Noah Syndergaard may just be the best Wild Card pitching matchup we've seen. Let's go position-by-position to see who has the edge.
Catcher
Buster Posey (115 Weighted Runs Created Plus, where 100 is league average) was the fifth-best hitting catcher of the 24 with at least 300 plate appearances, and is still regarded as a truly elite pitch framer (+25 runs, second-best in baseball), but he also had his weakest full season and went two entire months without a home run. Neither René Rivera (70 wRC+) nor Travis d'Arnaud (74 WRC+) hit even a little, however, so this is still lopsided in San Francisco's favor.
Big advantage: Giants
First base
If it seems like Brandon Belt never gets enough respect, that's probably true, because he stayed healthy and put up a star-level season (138 wRC+) that was actually about the same as what Paul Goldschmidt (134 wRC+) delivered. The Mets didn't place Duda on the roster, so they'll go with James Loney, a slick fielder who cannot touch lefty pitching. Still, Terry Collins (probably) isn't going to pencil Eric Campbell into the lineup. 
Big advantage: Giants
Second base
With Walker and Flores out, career Minor Leaguer T.J. Rivera has taken over at second base, and he's been stunningly successful, hitting .333/.345/.476 (119 wRC+), although in just 113 plate appearances. Joe Panik, who dealt with concussion issues this year, took a big step back, hitting .239/.315/.379 (90 wRC+) after his big 136 wRC+ 2015. Panik is the better player with the longer track record, though the Mets can hold out hope for the hot hand here.
Advantage: Giants

Shortstop
Though he's getting somewhat lost in the sea of new young shortstops, Brandon Crawford is an elite fielder with a strong arm (average of 86.7 mph, per Statcast™, fifth among regular shortstops) and a solid enough bat to be worth over 5 Wins Above Replacement, per FanGraphs. That's the fourth best among an impressive crop of shortstops, and it's his fifth straight year being average or better. That this is even a conversation says a lot about how great Asdrúbal Cabrera has been, as he's hit a scorching .347/.409/.639 since his trip to the disabled list, thanks to some real changes in his approach.
Small advantage: Giants
Third base
Both teams have a hot corner in flux. With Matt Duffy traded to Tampa Bay and Eduardo Núñez not available with a hamstring injury, the Giants will be forced to go with Conor Gillaspie and his career .308 OBP. Meanwhile, the Mets brought back old friend José Reyes, and he's been solid as Wright's replacement, hitting .267/.326/.443 (108 wRC+).
Advantage: Mets
Left field
After starting the year in center, Yoenis Céspedes has settled into left field, and he's been nothing short of outstanding, putting up a .280/.354/.530 (134 wRC+) line that's basically the same as during his stellar 2015, just with double the walk rate. It should be noted that Ángel Pagán bounced back from 2015's disaster to put up a league-average line of .277/.331/.418 (105 wRC+), but this one isn't close.
Big advantage: Mets

Center field
There's nothing ideal about having Curtis Granderson in center on defense, but the Mets' outfield alignment demands it, and he's put up a solid offensive season, popping 30 homers with a .237/.335/.464 (114 wRC+) line that closely matches his career averages. On the other side, Denard Span's Giants debut hasn't gone as well as expected, with his 97 wRC+ representing his lowest mark since 2013.
Advantage: Mets
Right field
Hunter Pence's wRC+ this year was 121; last year it was 125, and the year before that, 122. For his career, it's 121, which is to say that you know exactly what you're getting from him, and that's solidly above-average play. For the Mets, it's difficult to imagine Jay Bruce's first summer in Queens going any worse (.219/.294/.391, 82 wRC+), but in his past eight games, he's got 12 hits, including four home runs and a double, so perhaps he's heating up at the right time.
Advantage: Giants
Bench
The Mets have quietly built themselves a nice bench, though Flores would help here. Lagares provides elite defense, Kelly Johnson has quietly turned a miserable half-season with Atlanta (.215/.273/.289, 48 wRC+) into a productive one with the Mets (.268/.328/.459, 113 wRC+), and we haven't even talked about Michael Conforto, who remains a dangerous hitter against righties (career 126 wRC+). The Giants will counter with names like Kelby Tomlinson and Grégor Blanco, as late-season pickup Gordon Beckham is ineligible.
Advantage: Mets
Starting pitcher
We usually remind fans that in a one-game situation, the bullpens will be active early, with few starters asked to turn over the order more than twice. Of course, few teams have Bumgarner and Syndergaard, a pair of true aces who finished 3 and 4 in the National League in ERA, and so there's no real edge here. Barring disaster, it's difficult to see either Bruce Bochy or Terry Collins taking either out early unless the game is lopsided. On the other hand ... 

Slight advantage: Giants, due to Bumgarner's stellar postseason track record
Closer
Round and round the San Francisco closer carousel goes, and it appears to have landed on Sergio Romo, who has thrown six scoreless innings since getting his old job back. Either way, Jeurys Familia is near the top of the second tier of relievers just below the Britton-Jansen-Miller-Chapman group, as he's piled up 84 strikeouts in 77 2/3 innings while allowing just a single home run. Romo has the experience, but Familia has the stuff.
Big advantage: Mets
Relief pitchers
In a one-game situation, we could potentially see some starting pitchers throw innings, especially if Bochy truly doesn't trust his bullpen. (Surprisingly, Cory Gearrin who quietly struck out 13 of 24 hitters he faced since Sept. 1, didn't make the roster.) The Mets' relievers constantly feel like they're one man short, but Addison Reed (1.97 ERA, 91/13 K/BB) has been outstanding, and Hansel Robles and Fernando Salas offer some interesting stuff ahead of him.
Advantage: Mets