Tom Murphy The Catcher of The Future?

One of the biggest and most pleasant surprises of the 2019 season for the Seattle Mariners was the breakout of Tom Murphy. Tom Murphy came over to Seattle only a few days after the season began as the 3-0 Seattle Mariners acquired him from the San Francisco Giants for right handed pitching prospect Jesus Ozoria. The Giants themselves had only claimed Tom off of waivers from the Rockies four days prior. The expectation of most everyone going into the season is that Tom Murphy would be the backup and probably be about as bad as David Freitas and Mike Majarma were in years past filling in, for that role. Tom was not bad at all as he blew away every expectation to hit .273/.324/.535 his first season with the club and posted a 126 wRC+. He finished the season with 3.2 fWAR which ranked fifth among all catchers in 2019. His fWAR/162 of 6.8 led all catchers in the MLB last year. On a by rate basis, Tom Murphy was the best catcher in the MLB last year. So is it sustainable? At only 28 years old, one must ask the question, could Tom Murphy be the Catcher of the Future?

The first and probably most important thing to consider is the wear and tear of the catcher position. Tom Murphy only caught 67 games last year. The catcher position wears down on players when they are asked to play every day. We see this every year with part time catchers like Elias Diaz, and Max Stassi of all people last year will go off and then suck when asked to play every game the next year, the physical fatigue’s effect on a catcher is very significant and small sample results are not really at all predictive of how they’ll do in a larger role. Catching is hard and catching every day is harder so expecting Murphy to repeat that even if ignoring his platoon splits is a foolish dream. If he were to play left field and not catcher then the small sample stats might be predictive but Tom is a catcher and catchers are notorious for overperforming in small samples and having short peaks as the body will break down. His 2019 was undeniably great but the numbers need to be treated with a grain of salt simply due to his lack of wear and tear.

Now onto analyzing the underlying metrics and things don’t look too great on the surface a .301 xwOBA and a .340 BABIP don’t exactly scream sustainable. However, when you look deeper you start to see some upside and well he’ll never again be a 120 wRC+ guy most likely he could still be an above average hitter. His power is very real and very loud with 86th percentile exit velocity and believe it or not but his 22.2% HR/FB rate is also sustainable despite being almost 50% better than league average. The reason for this is his pull rate on flyballs that stands at an elite 42.1% which was sixth in the majors last year among players with at least 50 flyballs. This is significant because according to Travis Sawchik of fivethirtyeight.com, pulled flyballs become a homerun four times as often as those that are hit to centerfield and seven times as often as those hit to the opposite field. The average hitter pulls 24% of flyballs, Tom Murphy pulls 42.1% of flyballs. The only 5 players ahead of him in pulled flyballs outperformed their xwOBA’s by an average of .014 last year and that’s about where I would say Tom Murphy’s should have been in that .315 range. It doesn’t appear that his pulled flyball rate is a fluke either as he posted a not quite as incredible but still very good 37% pull rate on flyballs in 2018 at AAA. The power is for real and while he probably slightly overperformed in that area it’s not as much as people make it out to be.

His contact skills, however, are the big question mark for Tom and there is reason to believe major regression is coming for him in that department. His BABIP of .340 is unsustainable in its entirety and the standard deviation of his launch angle (Explained here by Alex Chamberlain of Fangraphs.com) is 51st percentile so something close to a league average BABIP is to be expected from him. There are some very real swing and miss issues with Tom Murphy and he’s not at all patient at the plate posting a 31% K rate and a 6.8% BB rate last year. His whiff rate of 31% is very bad and unless he suddenly learns to pick up spin it’s hard to see that going down at all. He is completely awful against breaking balls with a 38.3% whiff rate them and a .224 xwOBA and not much better on the offspeed stuff posting a 53.8% whiff rate on it but his average exit velocity on the rare changeup he hits is 93.6 MPH leading to a .291 xwOBA on them. His swing and take decisions despite his extremely bad plate discipline still is considered worth +5 runs on Baseball Savant so maybe there is some room to hope that the discipline numbers are misleading. He has very extreme platoon splits posting a 190 wRC+ against left handers in 2019 and a 70 wRC+ against righties but small sample platoon splits are notoriously noisy and he had reverse splits in the minors in 2018 so I’m going to assume this is mostly noise. The offense will for certain take a pretty big hit in 2020 as he is asked to catch full time and his luck regresses closer to normal but this should still be a bat with a wRC+ slightly north of the 85 catcher average.

His glove is what should make him still starting caliber as he has developed into quite the capable defender behind the dish. His framing per Baseball Savant was in the 73rd percentile and he saved 5 runs with his extra strikes called. Baseball Prospectus and Fangraphs both are a bit more bearish on him with Baseball Prospectus putting him at +3.5 runs and Fangraphs at +4.1 runs. He is exceptional at stealing strikes on the bottom edge of the zone, the best in the game there in fact with a 64.6% stolen strike rate in that zone which fits with the rotation the Mariners currently have in place very well as the staff is filled with sinkers down and lots of low breaking pitches. He’s a solid blocker for the little it’s worth as well with 0.8 EPAA runs above average per Baseball Prospectus (Errant Pitches and Passed Balls above average) and his arm is pretty decent despite below average pop times due to his accuracy. His arm totaled 4 DRS and 0.7 Throwing Runs above average on Baseball Prospectus which ranked 10th in the MLB among all catchers. His defense as a catcher gives him a high floor and his flexibility back there is highly coveted. Game calling is arguably the most crucial part of catching and well we don’t have any actual way to measure that available to the public and the only thing we have to go off of is vague reputations he still seems to grade out well. Mike Leake claims he is a good game caller and his pitchers had a FIP of only 4.67 when throwing to him which considering the AL average is 4.58 and Omar Narvaez (The Mariners other regular catcher) had a CFIP of 5.17 it’s pretty evident how impactful he was on the pitching staff. He’s also supposedly an intelligent person who works extremely hard in training to improve himself and is a leader in the clubhouse. Again not something, we can actually say if it’s true but that is what the evidence suggests. He won’t be Austin Hedges behind the dish but he also won’t hit like him and should as a whole be an above average backstop as a whole.

His 2019 wasn’t sustainable by a long shot and dreaming on the best catcher in baseball for the next half decade is foolish but he should still be a productive player nonetheless. I’m of the opinion that to maximize the effectiveness of your catchers you want to minimize fatigue and have your catchers split time. If the Mariners take that approach then we could see him sit at about a 100 wRC+ in the larger half of a time share, if not an above average backstop is still incredibly valuable even if he won’t jump off the page with his likely lack of elite offensive production. Pump the breaks a little on calling Tom Murphy one of the games best catchers, but don’t think that he is bad either- like most things the truth is somewhere in the middle. So the answer to the question is kind of and possibly, he is a Catcher of the Future but not the Catcher of the Future.