Last Updated on October 10, 2019 by Luke Arkins

Omar Narváez and Tom Murphy of the Seattle Mariners formed one of baseball’s best run-producing catcher combos this season. What might be in store for Seattle’s backstops in 2020 and beyond?

With Narváez and Murphy under club control through 2022 and 2023 respectively, the Mariners appear set for several years. Then again, GM Jerry Dipoto could address a more pressing need on his roster by trading one of the receivers.

Some fans might view moving Narváez or Murphy as too radical, even for the trade-happy JeDi. After all, the duo’s collective offense ranked near the top of baseball proving to be historically productive.

M’s Catchers Delivered Top-Shelf Offense

Still, it’s plausible the Mariners view their catcher depth as an opportunity to improve the roster. That’s assuming the club believes either Narváez or Murphy alone could deliver sufficient value to justify dealing the other player.

At first blush, the production numbers of Narváez and Murphy are impressive suggesting the club might be able to manage with just one of them. But a closer look reveals something Dipoto and his staff certainly have to consider before making any moves.

Left vs Right

The platoon splits of Narváez and Murphy indicate both players were significantly better against opposite-handed pitching this year.

Narváez & Murphy Platoon Splits
vs LHP
vs RHP

The left-handed hitting Narváez’s splits weren’t as drastic as righty counterpart Murphy. However, the native of Maracay, Venezuela faced left-handers just 79 times delivering significantly less power. It’s possible his numbers would plummet further with increased exposure to southpaws.

Murphy managed to hit seven homers against right-handed pitching, although overall productiveness ranked poorly. Among 192 righty bats with 140-plus plate appearances against right-handers, his 75 wRC+ ranked in the bottom 20-percent.

Clearly, manager and former big-league catcher Scott Servais did a splendid job of blending the skill sets of Narváez and Murphy into a core strength for the Mariners. But offense isn’t the only factor to consider. Effectiveness from behind the plate matters too.

Defense Department

Seattle catchers jointly ranked 27 of 30 in defensive runs saved (DRS). But there was a significant disparity between the club’s two main receivers. Advanced metrics suggest Murphy was superior compared to Narváez.

Omar’s & Tom’s Differing Defensive Stats

The first two stats on display after DRS are STATCAST products found at Baseball Savant – Framing and Pop Time.

Framing gauges a receiver’s ability to get borderline pitches called a strike by the umpire. Perhaps robot umps become reality and make catcher framing irrelevant. For now though, the skill remains valuable.

Pop Time essentially measures the throwing efficiency of catchers. It’s the time from the moment the catcher receives a pitch until his throw reaches the fielder’s glove at the center of the base.

Adjusted fielding runs above average (FRAA_ADJ) from Baseball Prospectus is a catchall metric (like DRS) capturing proficiency in framing, throwing, and blocking.

There is some redundancy between the metrics just presented. But I wanted to underscore a common theme using multiple sources. Essentially, Narváez’s defense doesn’t rate well regardless of measurement method.

Some may suggest Narváez improved from previous seasons. This may be true, but his defensive metrics still ranked near the bottom of the league this year. Meanwhile, Murphy placed in the upper 30-percent.

Measurable Outcomes

Framing, throwing, and blocking are often cited when assessing catchers. But I wanted to look at Narváez and Murphy through a different lens; the outcome produced by the pitcher-catcher relationship. To achieve this goal, I turned to my go-to stat – expected weighted on base average (xwOBA).

We know xwOBA reflects both quantity of contact (strikeouts and walks) and quality of contact (exit velocity and launch angle), which pitchers can influence to some degree. Therefore, it’s reasonable to presume battery-mates play a role too.

With this in mind, I compared the xwOBA of Seattle’s opponents when Narváez or Murphy were calling games. As with platoon splits and defensive metrics, the difference is noticeable.

When Narváez was behind the plate, opposing hitters had a .340 xwOBA (.319 is league-average). Conversely, a .327 xwOBA with Murphy – above the league norm, but considerably better than his partner.

From there, I went a step further scrutinizing the xwOBA of individual pitcher-catcher pairings. Since there was considerable turnover with Seattle’s pitching staff this season, I focused on the six pitchers with the most innings as a Mariner this year and one newbie important to the long-term plans of the club.

Let’s begin with three veterans, who aren’t part of the club’s future. In parentheses next to an xwOBA is the number of plate appearances a pitcher-catcher combo worked together.

 xwOBA Gaps For 3 Exiting Vets
Mike Leake
.402 (24)
.342 (549)
Wade LeBlanc
.340 (405)
.344 (126)
Félix Hernández
.370 (310)
.378 (15)
.354 (739)
.343 (690)

Before a July trade to the Diamondbacks, Mike Leake threw almost exclusively to Murphy. Perhaps the right-hander felt more comfortable throwing to the University of Buffalo alum. Then again, other factors may have influenced the decision to link the pair. It’s worth noting that Leake had a .347 xwOBA last year and .365 with Arizona.

It didn’t matter who was catching Félix Hernández or Wade LeBlanc. Both had disappointing campaigns and will probably pitch elsewhere next season. The notion of King Félix pitching with another club next year seems so odd.

Okay, we didn’t learn much from that comparison, so let’s shift our attention to a trio central to the Mariners’ future – Marco Gonzales and rookies Yusei Kikuchi and Justus Sheffield.

Just for kicks, I threw in pending free agent Tommy Milone. It’s possible Milone returns assuming both team and player desire to continue their relationship.

 xwOBA Split Noticeable With Younger Pitchers
Marco Gonzales
.321 (483)
.314 (301)
Tommy Milone
.327 (245)
.300 (147)
Yusei Kikuchi
.349 (409)
.338 (293)
Justus Sheffield
.362 (36)
.310 (132)
.333 (1173)
.319 (873)

Gonzales did slightly better with Murphy, but Milone’s xwOBA was significantly lower with the New York native calling his games.

Sheffield was better with Murphy too, although the Tennessee native didn’t work with Narváez as often as Murphy. Conversely, Kikuchi’s numbers were underwhelming regardless of catcher.

There are many reasons an xwOBA disparity may exist. Most Seattle’s starters weren’t power arms and therefore were heavily reliant on command and control to be effective. Perhaps the defensive acumen of Narváez and Murphy came into play.

A catcher’s framing ability could affect xwOBA if he’s not getting the close calls from umpires.  Moreover, confidence in a receiver’s blocking ability could influence pitch-selection and/or location in a positive or negative manner.

Let’s cover one more factor the front office may consider – help from within.

Internal Affairs

We’ve focused on Narváez and Murphy because they were the main stakeholders this season. But another player’s presence could affect management decisions – rookie Austin Nola.

Nola was primarily an infielder since turning professional in 2012. But he added catching duties to his repertoire three years ago in the Arizona Fall League. Since then, the LSU product has caught over 1,400 minor league innings, plus he made four starts with the 2019 Mariners.

Perhaps Dipoto and crew would mitigate losing one of their primary backstops by using Nola as the replacement. Then again, the 29-year-old played both infield and outfield corner positions, plus second base in addition to catcher this year. The team may prefer preserving its roster flexibility by keeping him free to move around the diamond on an “as needed” basis.

Another option may eventually be Cal Raleigh. Prospect Insider’s most recent rankings list Raleigh as Seattle’s tenth best prospect. But the former Florida State Seminole only joined Class-AA Arkansas during the latter part of this season. Raleigh doesn’t project as big-league ready, yet.

Moving Forward

The Mariners rebuild has many moving parts to it, including the catchers we’ve discussed. For this reason, how the organization ultimately decides to utilize its backstop inventory remains unclear.

Narváez has a record of offensive upside and therefore a surer bet to continue delivering plate production than Murphy next season. On the other hand, Murphy offers a superior defensive option.

Perhaps a stable presence behind the plate matters more to the Mariners than a consistent bat. Particularly with the rotation getting younger with Sheffield, Justin Dunn, and eventually Logan Gilbert entering the mix.

If forced to choose between keeping Narváez or Murphy, I’d select Murphy and explore trading Narváez. Dipoto likely recoups more value than he surrendered to get the Venezuelan from the White Sox last offseason – reliever Alex Colomé.

Yes, Murphy might experience a big drop in production when exposed to right-handers more often. But catchers typically deliver less offense than other position players. Solid catcher defense is more crucial to team success and Murphy is a better option than Narváez in that regard.

Moving Narváez wouldn’t necessarily mean Nola has to be the primary alternative at catcher. Dipoto could add another backstop keeping Nola available to play elsewhere, while remaining a third option behind the plate for Servais.

How Dipoto decides to utilize his deep stable of catchers this offseason should be instructive and fun – at least I think so. Does he move Narváez or Murphy? Will he keep both players? Could he formulate an innovative plan not conceivable by pea-brain?

Perhaps in the near future, we won’t be talking about the Mariners’ offseason moves in October because the team will still be playing.

Wouldn’t that be something?

My Oh My…



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