MJ Melendez fares poorly in new metric measuring catcher blocking

MJ Melendez had a terrific rookie season with the bat. He was one of the more patient hitters on the team and showed terrific power with 18 home runs, with an overall wRC+ of 99.

Defensively, however, Melendez struggled at the big league level. He had to split time between catcher and the outfield to get enough playing time with All-Star Salvador Perez behind the plate. He would end up playing 78 games behind the plate, but by most metrics, he did not play well defensively. We already knew he was not a good pitch framer, ranking dead last in baseball in pitch-framing metrics. But a new metric out today shows he also fared poorly in blocking pitches.

Baseball Savant now has a leaderboard for “Blocks Above Average”, measuring how well a catcher does at blocking pitches in the dirt. It measures how a catcher fared in giving up wild pitches and passed balls compared to how an average catcher would have fared. Mike Petriello explains it a bit here:

These blocking metrics are based on putting a difficulty number on each opportunity — based mostly on pitch location, pitch speed, pitch movement, catcher location, and batter/pitcher handedness, while considering only pitches where a passed ball or wild pitch is even possible, so excluding balls in play, fouls, bases empty pitches and so on — and by capturing that number on each pitch, noting the success or failure rate and adding them up, you can get to a season-long number.

The best in the game was Orioles rookie Adley Rutschman, who allowed just 25 pitches to get past him, while the average catcher would have allowed 43, for a net positive of +18. The worst in the game was Melendez, who gave up 54 passed balls and wild pitches, while the average catcher would have given up just 29, for a net negative of -25.

The first instinct would be to argue that perhaps the criticism lies with the pitching staff, which led the American League in walks and bounced more than a few pitches in the dirt. But Salvador Perez, who caught the same pitching staff, fares quite well in this metric. The five-time Gold Glover gave up just 30 wild pitches and passed balls, compared to 35 from an average catcher, a net positive of +5, 17th-best in baseball. Statcast also measures how difficult it is to catch a pitching staff, and the Royals pitching staff only ranks as the sixth-most difficult to catch. Despite that, the Royals far and away led baseball in wild pitches and passed balls with a combined 95, although they did also lead the league in block opportunities.

Melendez is young and athletic, and of course there is an opportunity to improve. The hiring of former big league catcher Paul Hoover to serve as bench coach was likely done with the thinking he can help Melendez improve defensively. But it probably shouldn’t be a forgone conclusion that his future remains behind the plate. His defensive metrics were poor in the outfield last year, but perhaps preparing for the position in spring training will allow him to improve his play there. Either way, the 24-year-old will need to improve with the glove if the Royals want to field the kind of elite defensive club they had when they won back-to-back pennants.