Exploring Royals Catching Metrics: Blocking

[Kevin O'Brien]

Image courtesy of Jayne Kamin-Oncea-Imagn Images

When it comes to evaluating catching defense, it can be a polarizing subject among baseball fans. Is a good catcher someone who can throw down runners and prevent stolen bases? Is it someone who can block balls and prevent wild pitches and passed balls? Or is it a player who can frame effectively and steal extra strikes?

According to Statcast, all three aspects are important to effective catcher defense and can be properly measured via appropriate metrics. When it comes to measurable catcher defensive metrics, Baseball Savant has four categories:

• Catcher Blocking
• Catcher Framing
• Catcher Pop Time
• Catcher Throwing

Catcher pop time and throwing can be lumped together effectively. Both present important information when it comes to the speed of a catcher throwing the ball to the infielder (pop time) and how accurate their throws are (throwing). Thus, one part of this series will examine both pop time and throwing metrics and how they work together to help a catcher limit runners on the basepaths.

However, part one of this post will focus on the metrics of a basic catching skill: blocking. It's something Little League catchers are first taught when they put on the catcher's gear. If a catcher can't block effectively, they won't last long at the position. 

Thus, I will take a look at catcher blocking metrics via Statcast, what they measure, who the top blocking catchers are in the league, and how Royals catchers fared in 2025. Lastly, I will predict the Royals' catchers' outlook in these categories based on these blocking metrics. 

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What are the types of blocking metrics?

When it comes to blocking metrics on Statcast, the most important metric is blocks above average. This metric shows how well a catcher prevents passed balls and wild pitches. The fewer balls that get by a catcher, the better they typically are when it comes to blocking and defense in this category.

Here's a breakdown of how Statcast calculates blocks above average.

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What is this? A Statcast metric designed to express the demonstrated skill of catchers at preventing wild pitches (WP) or passed balls (PB).

How this works: Every pitch is assigned a probability of being a passed ball or wild pitch based upon several inputs, most notably: pitch location, pitch speed, pitch movement, catcher location, and batter/pitcher handedness. Based on that knowledge, each pitch a catcher receives (or fails to) is credited or debited with the appropriate amount of difficulty. For example, if a catcher blocks a pitch that is a PB + WP 10% of the time, he will receive +0.10. If he blocks a pitch that is a PB + WP 90% of the time, he will receive +0.90.

How to read it: Blocks Above Average is the difference between actual PB + WP and estimated PB + WP based on opportunities seen. Blocks Above Average / game is a rate stat based on an average catcher receiving 40 blocking chances per game. Catcher Blocking Runs converts blocks to runs saved on a .25 runs/block basis

 

Based on this definition, blocks above average don't just reward blocking easy pitches; they also reward blocking difficult ones, and to a greater scale. Because blocking requires good instincts and athleticism, the more talented and agile catchers cannot only make the routine blocks but also the ones that save pitchers' butts (especially the wild ones with lackluster control). Therefore, the younger or less experienced a pitching staff is, the more important it is to have a strong blocking catcher.

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Who were the best blocking catchers last year?

I imported the blocking data from Statcast into Datawrapper. The only Statcast section I omitted was the difficulty of opportunities. The blocks above average, based on difficulty, seemed to adequately display which catchers were better at blocking the different types of pitches. 

Here's what the ranking of qualified catchers from last season looked like, as organized by blocks above average. 

 

The top five catchers in terms of blocking, based on blocks above average, were Alejandro Kirk (Blue Jays), Danny Jansen (Rays and Brewers), Tyler Stephenson (Reds), Dillon Dingler (Tigers), and Sean Murphy (Braves). All five of those catchers have blocks above average marks of eight or higher.

On the flip side, the worst five catchers included Connor Wong (Red Sox), Kyle Teel (White Sox), Martin Maldonado (Padres), Salvador Perez (Royals), and Agustin Ramirez (Marlins). Kansas City's own Perez had the second-worst blocks above average in baseball last season, with a -15 mark. Only Ramirez was worse, with a -28 mark (nearly double Perez's total). 

Perez has a solid defensive history in his career. He is a five-time Gold Glove winner, with his most recent coming in 2018. Unfortunately, in terms of blocking metrics, the Royals captain was among the worst in baseball last season. It's unlikely his blocking will improve much in 2026, especially since he will be 36 in May.

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How did Royals catchers fare in blocking metrics?

When it came to organizing Royals catchers, I kept the threshold low (1 minimum pitch) so I could see how all the Kansas City catchers did last year, regardless of sample size. Perez obviously showcased rough skills behind the plate when it came to preventing passed balls and wild pitches. However, was it a similar situation for others behind the plate in Kansas City?

Here's a look at how the four Royals catchers (Perez, Luke Maile, Freddy Fermin, and Carter Jensen) did last year in blocking metrics via Statcast. I did keep the Opportunity% numbers in this table (unlike the league-wide one), as I felt it was necessary given the wide range of sample sizes. 

Looking at the metrics, Fermin excelled most at blocking the ball. Not only did he lead all Royals catchers in BAA/Game (0.06), but he also had a 3 BAA, 1 BAA on medium pitches, and 1 BAA on hard pitches. He was the only Kansas City catcher with positive marks in those three categories. 

Maile was behind Fermin and ranked second in blocking metrics among Royals catchers. However, he still produced a negative value in this defensive category. He had a -2 BAA, a -0.12 BAA/Game, a 0 BAA on medium pitches, and a -1 BAA on hard pitches. He also had a negative value on easy pitches as well (-1 BAA). 

The biggest surprise of the group was Jensen, who actually rated worse than Perez in BA/Game with a -0.38 mark, 0.20 points worse than the Royals captain. His BAA of -2 matched Maile's mark despite seeing 317 fewer pitches. He also had the lowest easy opportunity% of the bunch, meaning he saw a higher percentage of medium- to hard-opportunity% pitches than the other three. That said, he also had the smallest sample, so it's likely that the easy percentage would have gone up had he seen more pitches behind the plate.

Regardless, while the sample size is small, the blocking metrics indicate that Jensen still has some work to do in this defensive category at the Major League level, especially in 2026. 

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What is the blocking outlook for Royals catchers in 2026?

Perez certainly isn't a good blocking catcher. However, the same can be said for Jensen, who was even worse than Perez, though the sample was a sliver of Perez's in 2025. To be frank, some of that is to be expected, especially since this was Jensen's first professional exposure not only to the big leagues but also to the Royals' pitching staff in a competitive environment. 

On a positive note, Jensen has demonstrated progress in blocking in the Minors. That is evident in his passed ball numbers from 2023 to 2025, which span from High-A Quad Cities to Triple-A Omaha. Let's break down his passed-ball metrics from each season and level.

• 2023 (High-A): 68 games, 593.2 innings at C, 16 PB, and 0.24 PB/G
• 2024 (High-A): 47 games, 406 innings at C, 4 PB, and 0.09 PB/G
• 2024 (Double-A): 26 games, 226.1 innings at C, 6 PB, and 0.23 PB/G
• 2025 (Double-A): 44 games, 393 innings at C, 3 PB, and 0.07 PB/G
• 2025 (Triple-A): 33 games, 274 innings at C, 4 PB, and 0.12 PB/G

For context, let's take a look at Jensen's trend in PB/G from that 2023 to 2025 period in the Minor Leagues, via Datawrapper.

 

An encouraging trend is that Jensen has bounced back in minimizing passed balls in his repeat of a level the following season. He improved by 15 points in High-A from 2023 to 2024. He improved by 16 points from 2024 to 2025 in Double-A. An encouraging part of his trend was that, while he had some regression in Omaha, he kept it below 0.20 (unlike his first stints in High-A and Double-A in 2023 and 2024, respectively). 

Thus, while Jensen has some work to do, he will have plenty of time during Spring Training in Surprise, Arizona to improve his blocking skills. Thus, he should see some improved blocking metrics at the MLB level as a result, especially as he gets a bigger sample of innings behind the plate for the Royals in 2026. 

How much will that improvement be? That is yet to be determined, especially since his sample was so small in 2025. However, Royals fans shouldn't discredit Jensen's blocking outlook because of his rough debut in this defensive category. 

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