Yainer Diaz Has Been a "Main Guy" This Season. And He's Deserved to Be One
The Astros catcher hits the ball hard despite chasing too many pitchers. Some have questioned his ability to handle a pitching staff, but he is not holding Astros pitchers back.
One of the big controversies among Astros fans in 2023 was whether Yainer Diaz should get more playing time. Dusty Baker preferred Martin Maldonado with his excellent reputation for handling pitchers. Thus, Diaz only started 85 games in 2023—42 behind the plate; 36 at DH, and 7 at first base.
There is no controversy in 2024. Early in the offseason, General Manager Dana Brown declared Diaz would be “the main guy next year.” And he has been. Joe Espada has written Diaz’s name into the lineup in 129 of the team’s 141 games this season. He’s 4th among major league catchers in games player and 5th in plate appearances.
Worth His “Main Guy” Role
With the question of whether Diaz should play well in the rear view mirror, we can now move on to more important questions like “has Diaz’s play been worth the trust that this general manager and manager have shown in him?” And the answer to that is absolutely.
Diaz has been worth 3.1 Wins Above Replacement this season, according to Baseball Reference’s measure. That’s tied for 50th best among all major league hitters and tied for 4th best among all catchers. Diaz is slashing .297/.324/.450 for a .774 OPS. His 118 wRC+ is tied for 7th best among major league catchers with 200 or more plate appearances.1
A Man of Extremes
In writing about Diaz last season, I described him as a “man of extremes…He is extreme in his power—among the best in the majors. And extreme in his willingness to swing at and chase pitches—also among the highest in the majors.”
Those characteristics—power and no patience—are in evidence this season again. Diaz’s Statcast metrics show he is among the best in the league at expected batting average (.299) and at hitting the ball hard (84%). That’s obviously a good combination—harder hit balls are more likely to become base hits. It also leads to a well above average expected slugging percentage (.467). Diaz hits the ball hard and that leads to more base hits and more extra base hits.
Diaz remains extreme in his chase rate—he is at the 1st (i.e. the lowest) percentile in this metric. Thus, he rarely walks—his 4.1% walk rate is at the 5th percentile. So while Diaz leads major league catchers in batting average, he is only 15th in on base percentage.
Diaz is not quite as extreme in his power hitting as he was in 2023—it’s still quite good. But he’s definitely extreme in his willingness to chase balls out of the strike zone.
Free Swinging, But Few Strikeouts
Further context for Diaz’s willingness to swing at pitchers is provided in the table below. Diaz swings at 57.7% of the pitches he sees. That’s the 7th highest rate among the 134 qualified major league hitters. He swings at 44.7% of pitches that are out of the strike zone—that’s the 4th highest chase rate in the majors. He’s only slightly choosier when the ball is in the strike zone—he has the 11th highest swing rate on balls inside the strike zone.
Pitchers have of course adjusted to Diaz’s free swinging ways. They have throw only 38.6% of their pitches to him inside the strike zone, the 126th highest rate in the majors (out of 134).
This combination should produce a lot of strikeouts. But it doesn’t for Diaz. One reason is that when when a pitcher throws a pitch in the strike zone, Diaz swings. He has the 8th lowest rate of called strikes. As a result, he gives away few strikes to pitchers. His 22.9% CSW% (Called Strikes plus Whiffs) is the 11th lowest in the majors. Pitchers do not often fool him into not swinging or swinging and missing .
This combination leads to a high average, low strikeout hitter. It also has limitations—he would get on base if he could let more pitches go. But his ability to make contact—even on pitches out of the zone—means that he doesn’t pay as big a cost for his poor swing decisions as other hitters.
Diaz’s defensive numbers also show extreme characteristics. The Statcast numbers show that Diaz is well above average at throwing out runners (79%) thanks to a very strong arm. He is also above average at blocking balls in the dirt (80%). These are valuable skills for a catcher.
But in many ways, the most valuable skill for a catcher is his ability to “frame pitches.” That is, to catch them in a manner that suggests to the umpire it was a strike, even if it’s off the plate a little bit. Diaz is not good at this skill. He is at the 1st percentile at framing among major league catchers.
Can Diaz Handle a Pitching Staff?
Of course, the skill that is often most meaningful for catchers is their ability to handle a pitching staff. Some of that is being a good pitch strategist and some of that is being essentially a psychologist. Maldonado was hailed for this skill—it kept him in the lineup more than many Astros fans desired.
Because these skills are qualitative and are based on personal conversations and emotional intelligence, it is hard for us to assess from the outside. At some level, it’s clear that Espada prefers Caratini for his skills at handling pitchers. For example, Caratini has caught each Yusei Kikuchi’s 6 starts for the Astros.
But there is also evidence that Diaz is gaining trust among his starting pitchers. For example, early in the season, Diaz only caught 3 of Framber Valdez’s first 14 starts. But starting on July 4, Diaz has caught 11 straight Valdez starts.
Those starts have also gone pretty well. Valdez has a 2.00 ERA in 72 innings, striking out 85 and walking just 21. Opponents have a .481 OPS against Valdez. In short, whatever limitations Diaz may have handling the notably mercurial Valdez, it’s not stopping Valdez from pitching like an ace.
And that lesson is not just applicable to Valdez, but to the whole pitching staff. Astros pitchers have a 3.67 ERA, 6th lowest in the majors. Diaz is not holding them back.
And when you put that together with his excellent bat, you get a All-Star level player. Diaz has been one of the “main guys” for the Astros this season, and thank goodness for that.
The catcher he’s tied with is his backup—Victor Caratini. That was—as I noted in the offseason—a good pickup by the front office.