Catchers (And Umpires) Are Remarkably Consistent

At every level of baseball, there’s much concern over a catcher’s health. There is less discussion on the in-game impact of those rigours than there is on how it affects durability. Any major league roster is called into question when it lacks a backup catcher. Part, if not most of that, represents a concern for a situation that might see the starting catcher unable to play. However, the other reason is to ensure the regular backstop receives sufficient rest.

In 2019, no position had fewer defensive qualifiers than catchers (ten). The leader in games played among those ten was J.T. Realmuto, who started 130 games. He remained healthy all year, though he spent a single day on the paternity list in July. (Even an extra game would still keep runner up Yasmini Grandal five starts back of the Phillie.) After starting 32 games on the bench, Realmuto’s 2019 season was tied for 42nd in games started among all qualified catching seasons this century – a total of 301. It’s nothing new and shouldn’t surprise anyone: Catchers need rest!

Nine innings behind the plate puts anyone’s body in a physically compromising situation. That’s what makes veteran backstops so rare and impressive. Yadier Molina is far from least among them. The Cardinals catcher currently sits seventh all-time in games caught, with the opportunity to move up a few slots in upcoming seasons.

Cred. Jeff Curry

The obvious comparison to catchers’ strenuous day-to-day duties would be that of pitchers’. The mechanics and biology of throwing a baseball beyond highway speeds are not exactly what our human bodies were made to do. In this way, catchers and pitchers have much in common physically. Circling back to Molina, to offer some context, those who accumulated the seventh-most innings pitched and games started on the mound are Don Sutton and Roger Clemons respectively.

Pitchers, especially in recent years, have undergone a revolutionary change. Their roles have been forever altered. Gone are the days of complete games and 200 pitch outings. Today’s pitchers are more like a loaf of bread than their predecessors a century ago, they carry a best-before date. Hitters become used to a pitcher’s slot, speed and style and greatly improve their success against him in successive rematches. But another aspect of the revolution is pitcher durability. You can squeeze a little extra cheese from a pitcher when they’re not being milked for innings. Also, their fragile ligaments carry only a limited number of pitches. Like catchers, pitchers need rest!

However, the two positions begin to diverge when analyzing the in-game impact of their workload. For pitchers, as already established, there is much incentive for limiting extended outings, be it through the lens of a single game or an entire season.

Do the physical limitations imposed by added or extended workloads apply to catchers too? It would make sense. Catching at least nine innings each day should result in a visible impact on catchers’ performance. Well, believe it or not, it doesn’t. 

Using the percentage of pitches thrown outside the strike zone that were called strikes and the percentage of pitches thrown inside the strike zone that were called balls, catchers are remarkably consistent:

Catchers’ performance (in 2019 anyway) didn’t at all degrade with each passing inning. They continued to frame at a similar rate and also maintained their ability to restrict a call going in the batter’s favour. One may claim that catchers were slightly better in later innings. Technically, they’d be right. In both means of measurement, there was an improvement. For framing, the poorest inning was the second, only 32.21% of pitches were framed, improving to 33.62% in the seventh. In the third inning, 1.88% of balls were within the strike zone, shrinking to 1.73% in the eighth. However, this is a very minuscule and more than likely insignificant change.

Because of this consistency, we can make the same conclusion about umpires. Umpires also fail to alter their calls as games progress. This is encouraging. The two men behind the plate can uphold their sharp abilities even through an entire nine-inning game.

Few tasks, nevermind physically exhausting tasks, can be completed with this degree of uniformity. It highlights the robotic-like abilities of both catchers and umpires, adding just one more layer to the already thickly laminated talents of these impressive individuals.

All data sourced from fangraphs.com, baseball-reference.com and baseballsavant.mlb.com.