Last Updated on February 27, 2020 by Jason A. Churchill

The return the Seattle Mariners received by trading Omar Narváez to the Milwaukee Brewers – a minor leaguer and a compensatory pick – didn’t sit well with some Mariners fans. But dealing Narváez had more to do with developing young arms than making a splash in the marketplace.

Sure, Narváez was one of the best hitting catchers in baseball last season. Among peers with 350-plus plate appearances, he was top-five in AVG, OBP, wOBA, and wRC+. But defensive issues continued to limit his overall value. Hence, the seemingly underwhelming yield from Milwaukee.

An Unexpected Comp

Instead of re-hashing Narváez’s defensive metrics (they’re bad), let’s consider the effect of 27-year-old’s work behind the plate on his overall value. This can be accomplished by comparing the 2019 version of Narváez to one of baseball’s best catchers – J.T. Realmuto.

Some may view comparing Narváez to a two-time All-Star and the owner of two Silver Slugger Awards as an exercise in futility. But as you’ll see, defense was the statistical difference-maker between the two this year.


Narváez’s 119 wRC+ suggests he was a superior run producer. Yet, Realmuto’s WAR (FanGraphs) screams he was far more valuable. Using another FanGraphs product, Defensive Runs Above Average (DEF), we can see why. Realmuto led 36 MLB catchers in DEF, while Narváez finished dead last.

Team Matters

Clearly, Narváez’s defensive numbers negatively affected his value compared to fellow catchers. But there’s a team dynamic to consider too. Deficiencies in game calling, blocking, and framing (key elements of advanced metrics) influence pitcher effectiveness.

As we’ve discussed in the past, expected weighted on-base average (xwOBA) reflects both quantity and quality of contact. Naturally, the pitcher-catcher combo influences these outcomes. In the case of Narváez and fellow backstop Tom Murphy, there was a distinct difference in opposing hitter xwOBA depending on who was calling games.

Sixteen Mariners pitchers currently on the roster appeared with the team this year. The following illustrates their collective xwOBA and how the group fared with Narváez or Murphy behind the plate.


Now, I’m not suggesting Narváez was the root cause of the Mariners’ pitcher woes last year – he wasn’t. But the metrics do imply the team’s staff performed better with Murphy donning the tools of ignorance.

Beyond the data, there’s anecdotal evidence suggesting Murphy was a better fit moving forward. Seattle Times beat writer Ryan Divish reports multiple pitchers preferred Murphy over Narváez due to the latter’s defensive liabilities and inadequate pregame preparation.

Essentially, the metrics and Divish’s reporting paint Narváez as a sub-optimal choice to serve in a mentoring role. With youngsters Justus Sheffield and Justin Dunn already with the club and top pitching prospect Logan Gilbert potentially joining them next year, it made sense to move Narváez now.

Unfinished Business

So where do the Mariners go from here? GM Jerry Dipoto will assuredly address catching depth. Even if the team retained Narváez, that would’ve been a “to do” item for Dipoto. Currently, the only backstops on the 40-man roster are Murphy and Austin Nola.

Murphy appears set to be the starting catcher with Nola potentially serving as his understudy. It’s plausible Nola’s positional versatility motivates the team to add another primary backup allowing the LSU alum to move around the diamond. Then again, Dipoto has signaled a comfort level with Nola spending more time at catcher next season.

Greg Johns of quoted Dipoto discussing Nola saying, “We’re very comfortable with him being a strong backup catcher.” Perhaps the Mariners already have their man and focus on acquiring organizational depth.


To be clear, Narváez has value. But at this point in the Mariners’ rebuild, the combination of strong offense and below-average defense wasn’t a fit with the club. That doesn’t mean he won’t help the Brewers contend next year.

The catcher market crested and Dipoto seized the opportunity to deal Narváez, who wasn’t prepared to help guide a young pitching staff. A logical move for a club reimagining its roster and culture.

Even if that catcher raked at the plate.

My Oh My…

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