The Miami Marlins signed a veteran in Michael Morse in the offseason to a not-unreasonable two-year, $16 million deal that would have had him be the team's first baseman for the short term. However, like Jarrod Saltalamacchia before him, the Marlins' free agent signings in the relative bargain bin did not work. Morse struggled out of the gate, got hurt, and never reestablished his position as a starter. Eventually, the team paid a draft pick to get rid of him to the Los Angeles Dodgers as part of the Mat Latos trade.
Part of the reason the Fish felt confident in getting rid of Morse was that they felt they had a capable replacement in the 26 year-old Justin Bour, who was initially acquired in the minor league portion of the Rule 5 draft from the Chicago Cubs before the 2014 season. Bour had a solid 2014 Triple-A season, hitting .306/.372/.517 (.379 wOBA, 124 wRC+) and that encouraged Miami, but not enough to go with Bour as a solo act at first base. The team opted for a free agent choice, but when Morse struggled, the team did not hesitate to turn to Bour for the season.
At the plate, at least, Bour did not disappoint. However, his season's batting line can be misleading.
The batting production cannot be questioned. Bour put up 23 home runs over just 446 plate appearances, putting him on pace for 31 homers per 600 plate appearances. That is the kind of left-handed power that the Fish have been searching for to complement Giancarlo Stanton in what has otherwise been a pretty pop-less lineup. Given the fact that Marcell Ozuna struggled so badly in his second full season in the bigs, getting the home run production and .218 ISO from Bour was a welcome sight. This marks the second time since 2011 that a Marlin other than Stanton has hit more than 20 homers in a season. Among first basemen in 2015, Bour's 117 wRC+ was 16th out 30 players with 400 or more plate appearances, meaning that he was about average for a first baseman in terms of batting line.
The rest of the line was acceptable as well, of course. Bour struck out in 22.6 percent of his plate appearances and only walked in 7.6 percent of them, but he contributed enough power in order to keep his like afloat despite a mediocre strikeout-to-walk rate. For a swing-first slugger, however, he made a reasonable amount of contact at almost 76 percent, about on par with players like Todd Frazier, Starling Marte, and Andrew McCutchen. In terms of his plate discipline, he combined Stanton's swinging tendencies this year with better contact, and that is not necessarily a bad place to be.
Of course, Bour is no Stanton in the power department, but the Marlins will not scoff at those 23 homers. However, not all offensive things were positive. Bour was charged with a pretty bad year on the basepaths this season, as the first baseman was tabbed for between four and seven runs below average in baserunning. The lumbering Bour never exactly attempted steals, but it was likely that he lost runs on not advancing on the bases, fulfilling the age-old description of sluggers "clogging" the bases. Bour got caught out five times on the bases and took only 15 percent of extra bases that he had a chance to snag. In particular, out of the 16 times in which a single was hit while Bour was at second, he advanced past third only six times, getting caught out at home twice in the process. Compare that to Realmuto, an above-average contributor who reached home on four of his 10 similar opportunities.
Still, offense overall was not Bour's problem. He was a minor net positive overall with his bad baserunning, as he was between two and five runs above average depending on your account of his baserunning. The additional question came with his defense. He was rated as one of the worst defenders at first base by most advanced metrics. UZR had Bour at about five runs below average, while DRS had him at seven runs and Baseball Prospectus's FRAA had him at four runs worse than average. The fielding numbers look bad when you look at rawer data as well. BIS data on fielding had Bour fielding 73.6 percent of balls in his zone of responsibility, which ranks 29th out of 31 first basemen with at least 500 innings played. He also rarely ventured beyond his zone, making one out-of-zone play every 128 innings or so. Compare that to an average-rated first baseman from this year like Miguel Cabrera, who made such a play every 55 innings.
Overall, Bour did not put up a great campaign thanks to these baserunning and defensive deficiencies. Not being able to nail his defense in his first season in the bigs was a major reason why his season was not as successful as the 23 home runs and the strong batting line pointed out. But as of right now, the Marlins owe him another full season to assess his future as a cost-controlled piece.