In 2021, Realmuto has been Salvy Perez, but with good defense

Salvador Perez is having an historic season. He now has 46 home runs, a new single season record for catchers. The record had stood for 51 years, since a 22-year-old Johnny Bench hit 45 in 1970.

Meanwhile, J.T. Realmuto is in the first season of a five-year, $115.5 million contract, and has had, according to some at least, a disappointing season.

Let’s compare Perez’s and Realmuto’s stat lines at the plate:

Perez.......... 642 PA, 46 HR, 117 RBI, .275/.315/.541 (.855 OPS, 126 wRC+)
Realmuto.... 520 PA, 16 HR, 72 RBI, .270/.352/.447 (.799 OPS, 113 wRC+)

The huge home run difference belies the fact that the two lines are more similar than different overall.

Even OPS, which has become a mainstream “advanced” stat, is misleading here. Because it’s a Frankenstein creation which double counts hits and undervalues getting on base, it shows an inflated advantage for Salvy.

Perez has hit for a lot more power. Realmuto has gotten on base a lot more. Overall, Perez has been better on rate basis, no doubt, but not significantly so.

Perez has also batted more, thanks to being in the AL and so getting the opportunity to DH when he’s not behind the plate. Perez only has 25 more PAs as a catcher, but 97 more in other positions (primarily as DH):

Perez............. 495 as C, 147 as DH/1B
Realmuto....... 470 as C, 50 as DH/1B

(In fact, 15 of Perez’ 46 HRs have come when he was DH-ing, not that detracts from the accomplishment.)

And in considering offense, there is also baserunning, where Realmuto has held the distinct advantage:

Perez............ -1.4 runs (below average), per the BsR stat at Fangraphs
Realmuto..... +5.7 runs

If we convert their stats to how many runs they’re historically worth, using linear weights, and scale both seasons to 650 PAs…

- Salvy has the big advantage in HRs (+24 runs)
- But JT makes up for it with other hits (+8), walks (+10), and base running (+8)

Bottom line:

The two have contributed the same offensively at bat for at bat, but Perez has batted more thanks to being able to DH a lot more.

In addition, of course, Realmuto rates as the much better defender, both according to Fangraphs, and also Baseball Prospectus. And as Leo wrote here recently, he is still limiting the running game.

Still the BCIB

Realmuto’s season should not be viewed as disappointing. Relative to the league, offensively it’s the second-best full season of his career (if only ahead of some other seasons by a hair):

1) 2018: .825 OPS, 127 wRC+
2) 2020: .827 OPS, 124 wRC+ (60-game season)
3) 2021: .799 OPS, 113 wRC+
4) 2016: .771 OPS, 111 wRC+
5) 2019: .820 OPS, 108 wRC+

In addition, he has been very effective with men on base:

With men on base... .289/.398/.492 (.891 OPS, 136 wRC+)
With RISP................ .296/.415/.470 (.885 OPS, 133 wRC+)

Is he still the “BCIB”? There has certainly been competition this year, with Will Smith putting together another strong season, a resurgent Buster Posey, and of course Perez.

Nevertheless, coming into play today Realmuto leads the majors in WAR for catchers, according to fangraphs, and has as strong a claim as anyone to the title.