Earlier this week, we discussed the Miami Marlins and their considerations on how to improve their roster around Giancarlo Stanton. One of the ideas discussed internally was to move outfielder Christian Yelich to first base, which was a position at which he spent significant time during high school before being drafted by the Marlins in 2010. The Fish recognize that Garrett Jones has been a major disappointment in 2014 and could look to upgrade, and Yelich's versatility opens up the team's spots for upgrade.
The Marlins want to add another bat this offseason and would be open to movingChristian Yelich to first base --– where he played in high school --- if they have better luck finding a quality free-agent left fielder than first baseman. One problem is that disappointing Garrett Jones is due $5 million next season. The Marlins would like to upgrade there nevertheless.
The Fish are right to want to upgrade on Garrett Jones, especially since he is not capable of hitting left-handed pitching and had an awful year in 2014. But moving Christian Yelich to first base would be a mistake the team should actively try and avoid.
We have already discussed what has made Yelich a four-win player in 2014, depending on what source you ask. The secret to Yelich's 2014 success is his balanced, positive contributions in almost every category, offensively and defensively. Yelich has been a balanced star this season, and part of that has been due to his excellent play in left field this year. Depending on what defensive metrics you use, Yelich has been worth between two and 11 runs above average. If you buy that he has been among the best defenders at his position this year, then he is bringing tremendous value with his athleticism and contributing to one of the best outfields in baseball.
As a left fielder, Yelich has defensive value. If you move him to first base, he becomes less valuable as a defender in two ways. For one, the pool of players who can play first base is larger than those who can the outfield, so that makes first basemen inherently less valuable. That is reflected in most Wins Above Replacement metrics as a positional adjustment. In FanGraphs' version of the metric, playing left field for a full season versus playing first base is worth five more runs. Yelich loses those five runs in the transition.
Then you have to factor Yelich's defensive play at first base. He has not played the position regularly at any point since becoming a professional baseball player. Furthermore, the range of defensive play at first base is smaller than the range in left field. The best first basemen in baseball may be worth 10 runs per season better than average and vice versa, according to UZR. The best outfielders in baseball may be closer to 15 runs better than average per year. That may be because there are more mixes of bad outfielders with rangy athletic ones, but it also may be because first basemen naturally get fewer opportunities than in other positions or opportunities that are easier or less valuable than in the outfield.
Finally, Yelich's skills in the outfield are less likely to translate into equivalently better performance at first. Yelich is already an athletic, above average outfielder due to his smart play and speed. That speed is less useful when you are covering as little ground as you would be at first. It is unlikely that Yelich is the best first baseman in baseball, but that is what he may have to be to make up the runs lost from going down the positional ladder.
Luckily, the Marlins can still find an outfielder or infielder who can eventually fill their first base need without needing to shift Yelich to first. Among the league's free agents this offseason, there are a number of corner outfielders who are significantly worse defenders than Yelich. Guys like Nelson Cruz, Michael Cuddyer, and Mike Morse are natural first base / DH types who could be moved there if the Marlins desired.
Better yet, Miami can explore the option of moving another player to first base. Casey McGehee is not exactly a Gold Glover at third base, and he is more familiar at first than Yelich, which should make his transition smoother. And it just so happens that there are a number of third basemen available in the free agent market this year, ranging from defensive wizard Chase Headley to all-around players like Pablo Sandoval. Acquiring a player at third and shifting McGehee to first remains an option.
Miami can turn to a lot of other sources for first base help before they resort to down-shifting Christian Yelich. Why waste a talented defensive outfielder when any number of players can play first base for this team? The Marlins should explore all other options first.