Is Geraldo Perdomo Still Pesky?

During the 2023 offseason, I put together a little metric I called Pesky+ with the intention of trying to encapsulate and enumerate Geraldo Perdomo’s ability to be a pest in the batter’s box. Back then, Geraldo Perdomo was firmly entrenched as a back of the lineup savant who seemed to always be a tough out even though he never really seemed to be a threat to do much damage himself. His ability to turn the lineup over to Corbin Carroll and Ketel Marte seemed to be the spark plug that allowed the Diamondbacks offensive engine to ignite and run at peak efficiency.

For those of you who have been around since 2023, you may remember that in that Pesky+ metric Geraldo Perdomo was the single most pesky player in the entire sport (I’d link the article but it appears to have disappeared somehow). Then when I ran the numbers again in 2024, his peskiness was only surpassed by Steven Kwan. Domo’s ability to only swing at strikes, rarely miss when he did swing, and see a ton of pitches made him truly elite at being a pest in the batter’s box.

Over the last couple years, Domo endeared himself to Diamondbacks fans for this ability to get the job done even though the impact rarely showed up in the box score. We loved him, but he was barely a league average hitter (95 and 100 OPS+ in 2023 and 2024, respectively). We commonly referred to him as the league’s best No. 9 hitter, but we may have secretly wondered if that was all he would ever be: a pesky hitter relegated to the back of the lineup but never a top of the lineup run producer. That all changed in 2025.

Geraldo Perdomo had an incredible breakout in 2025, going from a 2ish WAR player with a career OPS+ of 84 to a 7 WAR MVP candidate with an OPS+ of 136. I doubt anyone, even his most ardent supporters here on the ‘Pit, ever expected that kind of production. Much of this jump in production could be accredited to his jump in power. His slugging percentage jumped up nearly 90 points from 2024 and his ISO was up more than 70 points. In his entire career coming in to 2025, he had hit only 14 home runs; in 2025 he hit 20. For many players, getting a power surge of this magnitude would likely mean that they had to sacrifice swing control. Instead of focusing on getting the bat on the ball, one would focus more on getting a powerful swing off. Very rarely can players do both. Well, friends, I’m here to tell you that Domo somehow pulled that rare feat off.

I ran the Pesky numbers for 2025, and I honestly expected a drop-off in Perdomo’s numbers. I mean, he would probably be in the top-10 or -20, but I didn’t think he would be leading the league. There had to be some consequence of swinging for more power, right? Wrong. In 2025, Geraldo Perdomo led all qualified hitters in peskiness:

A quick refresher on how I calculate peskiness: I take the total percentage of pitches that a hitter swings outside the zone at and the total pitches that a hitter whiffs on then scale that based on how many pitches a hitter is able to see per time in the box. The idea is that pitchers ideally want hitters to swing at pitches that are outside the strike zone and, when they do swing, the more often a hitter misses, the less of a threat they are. The more often a hitter avoids doing those things, and the longer he drags out an at bat, the more of a pain he is to deal with for a pitcher. As you can see in the chart of the top-10 Pesky hitters in MLB for 2025, Geraldo is elite in each of those metrics resulting in him regaining the Pesky throne.

When I saw that Domo was incredibly able to maintain the quality of his at bats, I had to dig a little deeper and see how he was able to add significantly more power. Looking at Baseball Savant data, one number that stood out was the difference between Perdomo’s swing speed on HRs compared with his swing speed on all other swings. Swing speed data is relatively new, with only a couple seasons worth of data available to the public. Here is Geraldo Perdomo’s swing speed data each of the last few seasons:

Looking at this table, we can tell a few things we can tell about Perdomo’s swing. First, while he has consistently swung faster from the right side of the plate, the splits are remarkably consistent. Domo averages about 0.6 MPH difference between his swing speed from the left and right batter’s box. Compare that to Ketel Marte, who had a split of 7 MPH between swing speed on the left and right side of the plate! Secondly, and probably more important to this discussion, Perdomo dramatically increased his swing speed on home run swings. Each of the first 2 seasons, we see that the split in swing speed from home run to non-home run was right around 2-2.5 MPH. This season, those splits grew to 4-5 MPH. How rare is that? The league average swing speed split between homers and non-homers in 2025 was 2.8, basically right where Perdomo has been for the last 2 seasons. In 2025, his overall split of 4.3 MPH was 12th-highest out of over 140 qualified hitters in MLB.

Perdomo’s top-end swing speed hasn’t changed much over the past couple seasons (only 2 swings faster than 80 MPH in each of the last 2 years), but he has shown more ability to harness his power and turn it into positive results on the field. Of Perdomo’s top-10% highest speed swings of 2024, he only registered a hit in 14%. In 2025, that number grew to 22%. As he’s grown older and more into his physical prime, it appears he’s been able to focus more on dialing in his coordination instead of trying to dramatically boost his swing speed. Domo resisted the allure of the long ball and instead refined and built on his already elite foundational skillset and I think this was the biggest reason for Perdomo’s growth from local fan favorite to All-MLB caliber talent.

Geraldo Perdomo’s strong ability to be a pest in the batter’s box used to be his best offensive skill. Now, he’s grown into a more powerful version of himself which has made him one of the best hitters in all of baseball. I used to put a cap on what I thought was possible for Perdomo, but after 2025, I’ve been proven foolish and I’m excited to see how he wows us all in 2026.