Jeff Mathis is the worst hitter in baseball. He has one of the worst catcher's arms in baseball. Yet still, Jeff Mathis is the on the Rangers' 40 man roster, and he will likely be on their opening day roster as well.
He wasn't always bad at hitting. In the minors, Mathis had a combined .781 OPS. It's funny because Mathis actually has more PA in the minors than the majors. That's how much he gets sent down. His combined minor league OBP is actually .337, which isn't bad for a catcher. But in the majors, Mathis struggles heavily with the bat.
Jeff Mathis has never had more than 328 PA in a single season. Because of this, a "full season" for Mathis is upwards of 200 PA.
What if I told you that the highest OPS that Mathis has had in his 9 full years of playing was .642? And then what if I told you that he played in 93 games in a year that he had an OPS+ of 38? You'd think I was kidding. Go ahead and check baseball-reference if you want. That's not going to change his poor batting career.
Let's get into some career stats. In his career, Jeff Mathis has slashed .195/.254/.299 with 50 HR in 2938 PA. He has had a career OPS+ of 48, to go with a career 29% strikeout rate. That K% surprised me, so I decided to look at some more advanced metrics.
I decided to look on FanGraphs, where I saw that Jeff Mathis has a career 46 wRC+. Let that sink in. Furthermore, he hit 23.3% soft contact in 2019. He's also below average for medium and hard contact as well. He doesn't really walk, and his average just won't make up for it.
So why is Jeff Mathis still in the league? It's simple, really. He's a very good catcher. In short, he makes his teammates better.
The Rangers in general were an average team in 2019, but their pitching was a disaster. They had a team ERA of 5.06, and their FIP doesn't make up for it either. The only 3 pitchers that actually had an above average season were Lance Lynn, Mike Minor, and Chris Martin.
I know that catcher's ERA isn't the best thing to look at, but it generally shows if a catcher is good or not. It's good at comparing catchers on the same team, just not catchers on different teams.
When this pitching unit pitched to Isiah Kiner-Falefa, they had a 5.64 ERA. When they pitched to Jose Trevino, they had a 5.56 ERA. When they pitched to Tim Fedrowicz, they had a 6.74 ERA. But when they pitched to Jeff Mathis, they had a 4.10 ERA.
When the Rangers signed Jeff Mathis, they didn't know that Mike Minor would go from an average pitcher to an all-star because of Jeff Mathis. They didn't know that Lance Lynn would go from a washed up player to 5th in the Cy Young voting.
I attribute this to something that I call the Mathis effect. In his first full year, 2008, Mathis was on the Angels. That year, Ervin Santana went from a 7-14 record with a 5.76 ERA in 2007, to 16-7 with a 3.49 ERA and an all-star appearance in 2008. In 2009, Jered Weaver broke out. In 2010, Dan Haren was traded mid-season following a 7-8 start with a 4.60 ERA, and he ended up 5-4 with a 2.87 ERA on Mathis's Angels.
In 2011, Mathis made a good pitching staff great again with Jered Weaver finishing second in the Cy Young voting. In 2012, Mathis went to the Blue Jays where Brandon Morrow broke out with a 2.96 ERA. And of course, who can forget 2013 where Mathis developed a young Jose Fernandez? In his next full year, 2017, Mathis guided Zack Greinke from an off year in 2016 to an all-star appearence, and 2018 was the year that Clay Buchholz had his unsustainable 2.01 ERA in 16 GS. And of course, in 2019 Mathis guided Lance Lynn and Mike Minor to top 8 Cy Young finishes.
Wherever Jeff Mathis goes, good pitching follows. That's the Mathis effect, and that's why teams want Jeff Mathis on their squad.