Joe Mauer is having his best season as a first baseman

Joe Mauer used to be one of my favorite players. My favorite position is catcher, and he was one of the best pure hitters in baseball while playing the position. In fact, he is arguably the best pure hitter to ever play the position of catcher. To be clear, what I mean by “pure hitter” is what you get if you ignore power and focus solely on the hit tool. He was one of the best contact hitters in baseball during his prime. He even walked more than he struck out!

Catchers who can hit are usually poor defenders. Think Jorge Posada, or Mike Napoli back when he was a catcher. But that did not apply to Mauer. He was not just passable, either. He was actually a good defensive catcher. He led the league in caught stealing percentage twice, and he was a good pitch-framer on top of that. So in his prime, he was a good defensive catcher, with great plate discipline, and an even better bat. That is pretty awesome even if you do not have an affinity for catchers.

Despite his success, everything started going downhill for Mauer as a catcher starting in 2011. He only played half the season due to multiple injuries and medical ailments (including numerous head injuries and concussions). It was not even a good year at the plate for him, as he was only a league-average hitter. His catching duties decreased in 2012 and 2013 until he was made a full-time first baseman in 2014.

Byron Buxton is the future of the Twins, for better or worse

Photo by Hannah Foslien/Getty Images

Minnesota’s surprising success over the last month shows just how tightly their future outlook is tied to Buxton’s career trajectory.

I was pretty disappointed when it was announced Mauer would not be catching anymore. Don’t get me wrong, his concussion history made it the right decision, it just stunk that one of my favorite players would no longer be playing my favorite position.

I was also concerned about how this move would affect Mauer’s Hall of Fame case when the time came (we’ll discuss that next time). Obviously going from one end of the defensive spectrum to the other wreaks havoc on a player’s value. Per the WAR model, that is a drop of 25 runs per year. In reality, the actual drop is considerably less than that because the positional adjustment is dependent on the number of innings played at a position. If we take Mauer’s average yearly positional adjustment when he was a full-time catcher, and compare that to his yearly positional adjustment as a full-time first baseman, the difference turns out to be 14 runs.

Had I written about the Twins’ decision to move Mauer to first base in 2014, I probably would have written something like this: “Mauer has the OBP to play anywhere, but he does not have the power to play anywhere. However, if the position move results in less time lost to injury and an even better bat due to decreased wear and tear, that could do wonders in making up the loss of positional value. This also assumes that he will be at least an average defender at first, which is probably a safe bet. What is not a safe bet is that Mauer will still be worth 5-6 WAR. That is a best case scenario that probably will not happen.”

Obviously the best case scenario did not happen. From 2014-2016 he hit .267/.353/.380, which made him roughly a league-average hitter during that time. That is not a disaster, but that is also not good for a first baseman making $23 million a year. His .113 ISO ranks as the 39th worst over that three-year span. Taking a look at the bottom 50 in ISO, Mauer is one of the the few on that list that is not a bench player nor a player at a premium position. If we look at just the first basemen, only James Loney and Chris Johnson had a lower ISO, and they played in over 50 fewer games.

After averaging only 2.0 bWAR per year from 2014-2016, Mauer is already at 3.0 bWAR for 2017. He is hitting .304/.384/.414, which is far from vintage Mauer, but is a solidly above-average line nevetheless. The power is still absent, unfortunately, as he only has 6 HR and .110 ISO. Still, that is not bad value for an excelling Twins team that currently has the second Wild Card slot and is favored to hold it.

Mauer is about to go into his final season of his big contract in 2018. Unless we see vintage Mauer reappear, his future after that appears murky. I would not be surprised if he chooses to retire, especially if the Twins do not re-sign him. Minnesota has been home for his entire life, so he might not want to play anywhere else.

If Mauer does choose to continue his career after 2018, his prospects will be slim. The good news is that he will not have much competition that year in free agency at first base. The bad news is that the 2019 free agency class will be loaded, with Bryce Harper headlining it. Furthermore, first base is the easiest position to fill, and Joe Mauer will be a 36-year-old who does not hit for much power, and suitors will certainly question his future defensive value. Anything he is offered might not be seen as worthwhile to somebody who will have made $218 million in his career.

Minnesota’s native son has not exactly been the most popular among Twins fans in recent years. A big contract without big production does not tend to endear a player to fans, especially for a team that spends less than most other teams. I am not going to tell fans how to feel about players, but the fact of the matter is that Joe Mauer is one of the greatest Twins of all time. He will definitely have his number retired. He will soon pass Sam Rice as the fourth-best Twin by Baseball Reference WAR, and the third best in the live-ball era. (Walter Johnson played most of his career when the game was very different, and it was with the Washington Senators, the team the Twins used to be before 1961.) Hopefully time grant some perspective to how good he was with the Twins.