Diamondbacks Shortstop Geraldo Perdomo Quietly Having Exceptional Year

Though they remain on the outskirts of the NL wild card race, 2025 clearly hasn’t worked out as planned for the Arizona Diamondbacks. Their pitching staff has been decimated by injuries, potentially wasting incredible seasons from Corbin Carroll, Ketel Marte and perhaps most of all, shortstop Geraldo Perdomo.

Some eyebrows were raised when Perdomo signed a four-year, $45 million contract extension that runs through the 2029 season. That deal seems destined to be an incredible bargain from the Diamondbacks’ perspective.

From the first time I ever watched him play, Perdomo struck me as one of “those” guys – nothing flashy, especially on the offensive side of the game, but he just exudes advanced knowledge of the game. He grinds out quality at bats, and is always in the right position and thinking a play or two ahead on defense or on the bases.

Each season I prepare a list of top minor league position player prospects, based solely on offensive production relative to league and level, adjusted for age. Perdomo made my list twice, peaking at #70 in 2019. That’s a pretty strong peak ranking for a shortstop, as my list doesn’t adjust for position.

I recently published my monthly update of the NL MVP race, and Perdomo narrowly failed to crack my Top Ten, finishing 11th. He just might be on my year-end ballot.

Now one might say, Perdomo doesn’t impact the baseball significantly, and my rankings rely heavily on batted ball authority, so how the heck does Perdomo fare so well? Well, there are a few reasons.

Most years, there typically will be a shortstop or two who will rank highly on my personal MVP ballot despite ordinary peripheral offensive metrics. Dansby Swanson is a case in point, and even Francisco Lindor has merely been an average range ball-striker in recent seasons. When a shortstop is in that average range offensively, defense and positional adjustment can push him over the top.

First and foremost, Perdomo possesses arguably the single greatest ability – availability. Through Sunday, he had played 155 games and amassed 692 plate appearances – he’s punching the clock each and every day.

And what he lacks in batted ball authority, he makes up for with an elite K/BB profile. It’s a really big deal in this day and age to walk as much as you strike out – almost no one does it, and if one does, he barely does so. Ramirez has 92 walks versus 76 strikeouts this season – his 13.3% BB rate is nearly two standard deviations higher than league average, and his 11.0% K rate is over two standard deviations lower.

With that in your pocket, it’s pretty tough to be an unproductive hitter. In fact, it’s pretty tough to be a below average MLB hitter. Though Perdomo’s overall average exit speed of 85.7 mph is over a standard deviation lower than league average (as is his 87.8 mph average fly ball exit speed), he has compensated in other ways. His 93.3 mph average line drive exit speed is in the league average range, and his 23.5% liner rate is over a standard deviation higher.

Sure, there’s been some good fortune in his offensive numbers this season – adjusted for context, he has a 79 Adjusted Contact Score (vs. 98 Unadjusted) and a 112 “Tru” Production+ (vs. 138 wRC+). But guess what – that’s still a comfortably above average bat, and not just for a shortstop. Add in that defensive/baserunning value and positional adjustment, and he’s a legit participant in the MVP discussion.

Note the relationship between Contact Score and overall production when you have such an outstanding K/BB profile. A 20% below average Adjusted Contact Score magically transforms into a 12% above average overall offensive player. It’s a pretty big deal.

Moving forward? Well, that liner rate is going to come down toward league average, making him an average range offensive player, which is just fine. With all the extras he brings to the table (I mean, he has 19 homers and 26 steals to date), he’ll still rate as an above average all-around player, though he might not be a regular contender for the MVP ballot.

In an era where everyone is swinging for the fences and for launch angle, it’s refreshing to see someone getting it done the old fashioned way. And while many of the launch angle guys tend to burn out early, Perdomo has a skill set that should pass the test of time, and is a good bet to still be burning bright once his contract expires around his 30th birthday.