I’ve been fascinated by the idea of mirror image twins since the Giants signed Taylor Rogers last December, pairing him up with his brother Tyler and illuminating me to their unusual genetic connection. As monozygotic (i.e., identical) twins, they come from the same fertilized ovum and, thus, the same DNA. Taylor, however, is left-handed, and Tyler is right-handed, a manifestation of their mirror image relationship.

Mirror image twinship makes for a perfect metaphor, and as a writer, nothing excites me more. It’s like a real-world example of a contronym, a word that can have two opposite meanings in different contexts; the word “dusting” always looks the same, but sometimes it means to remove dust, and other times it means to sprinkle it on. It’s the same thing with the Rogers twins. They look exactly the same until they take the mound.

Taylor Rogers relieving Tyler Rogers today.

Hitters be seeing this… ? pic.twitter.com/5Tyq6S3RTD

— Rob Friedman (@PitchingNinja) July 16, 2023

The opposite handedness can be ascribed to genetics; the submarine thing, not so much. But that’s why the Rogers brothers are so interesting. Their mirror image relationship goes beyond heredity. From a box score or the back of their baseball cards, they’re almost indistinguishable. Both pitchers predominantly rely on a sinker and slider/sweeper, and with that two-pitch combo, they’ve earned similar results in 2023:

But they’ve taken two completely different paths to reach those results. While they work with a similar arsenal, Taylor always leads with his sweeper; Tyler leans on his breaking ball against same-handed hitters and his fastball against lefties. Taylor, the elder Rogers twin by 30 seconds, also throws his pitches with much higher velocity and a much higher arm angle. His goal is to rack up strikeouts, but his ever-so-slightly younger brother pitches to induce weak contact:

The same, yet completely different. It’s a fun relationship to discover. And the Rogers brothers aren’t the only mirror twins in Major League Baseball, even if they are, technically, the only mirror image twins in Major League Baseball. Indeed, another captivating pair of pitchers is showing off what makes them so similar and yet so different, and they’re doing so on a much bigger stage: Spencer Strider and Justin Steele.

Steele and Strider don’t look much alike. They were born on different days, in different years, in different cities to different mothers. Yet, in many ways, they’re twins. They sit beside one another on the NL WAR leaderboard and the NL Cy Young projector, trailing only Zack Wheeler on the former and Blake Snell on the latter. They are the only two qualified NL starters with a FIP below 3.00 and a winning percentage above .750. I would also argue they’ve been the two most compelling pitchers to watch in the NL this season. Snell’s performance has been a sight to behold, but all the underlying numbers suggest he’s pitching over his head. Meanwhile, Wheeler has just been classic Wheeler, and Logan Webb looks like typical Webb. In contrast, Steele has broken out as a bona fide ace, surpassing all preseason expectations, and Strider is proving his dominant rookie season was no fluke.

On the surface level, Strider and Steele have similar arsenals and approaches. Each is essentially a two-pitch pitcher, leading with a four-seam fastball and complementing the heater with a slider. They both dial up their slider usage when they have the upper hand, either with two strikes or the platoon advantage. What’s more, they locate their pitches in a similar fashion, albeit in a mirror image of one another. Strider, the righty, is pictured on top; Steele, the lefty, is down below:

During each of their prospect days, most evaluators saw Strider and Steele as potential relievers due to their limited arsenals. Each has played around with additional pitches, too, specifically against opposite-handed hitters, but they’ve done their best work by leaning on their best pitches. Perhaps they’re more predictable than most starting pitchers, but nevertheless, they know how to make opposing hitters play right into their hands. Each has a swing rate of about 52% against his slider and 54% against his fastball. That puts them first and second in the NL in total combined swings against the two pitches; no one else comes within 300 swings of Steele or 400 of Strider. Overall, only one qualified NL pitcher, Sandy Alcantara, has a higher swing rate.

But when it comes to the results of those swings, that’s where the similarities end. Strider aims for swings because he wants swings and misses. He’s a power pitcher through and through, with 93rd-percentile fastball velocity, a 99th-percentile whiff rate, and a 99th-percentile strikeout rate. We live in a strikeout-heavy era, and no one embodies the zeitgeist quite like Strider. He’s the only pitcher in history to record 200 strikeouts in his first 130 innings of the season, and he’s already done so twice in his two-year career. His walk rate, home run rate, and hard-hit rate are all respectable but unspectacular; strikeouts are the backbone of his game.

Steele, on the other hand, induces swings so he can generate groundballs. He has both one of the five highest groundball rates and one of the five lowest fly ball rates among NL starters, giving him the third-highest GB/FB in the league. He stands in stark contrast to Strider, who has the lowest groundball rate and the highest fly ball rate on the Senior Circuit. Steele isn’t a wizard at limiting hard contact, but since his average launch angle is so low, he leads all qualified pitchers with a 5.2% barrel rate, and he boasts the lowest home run rate in the NL. For the southpaw, his strikeout rate is respectable but hardly spectacular as his walk rate ranks in the 93rd percentile.

Strider and Steele accomplish such different goals with such similar approaches because of how different their individual pitches are; their four-seams and sliders are alike in name only:

Strider challenges batters with a blistering fast four-seamer that looks even faster thanks to his 93rd-percentile extension. He uses backspin to induce a rising effect, tricking his opponents into swinging under the pitch. Then there’s his slider, which is so hard to hit because of how well it plays off his fastball. The two offerings look similar out of his hand but come in at wildly different speeds in wildly different locations. On its own, his slider doesn’t seem like it should be so devastating, yet it’s been one of the least hittable pitches in the game; only Kodai Senga’s forkball has a higher whiff rate (min. 400 pitches). When they do make contact, opposing batters can hit Strider pretty hard and pretty far, but that whole “making contact” thing is just so damn tough in the first place.

Meanwhile, Steele’s four-seamer is so unusual that several people have compared it to a cutter or a sinker instead. Indeed, he can throw the same pitch with two different movement profiles depending on where he wants it to end up. His slider isn’t as different from his fastball as Strider’s, but he throws it with so much glove-side movement that batters struggle to get the barrel on the ball. His whiff rate isn’t as high, but his xwOBA on contact is much lower; among qualified NL starters, only Miles Mikolas has a lower xwOBAcon on sliders.

As the cherry on top of the Strider/Steele comparison, each ace’s unique style makes him wonderfully well-suited for his respective teams. Atlanta’s biggest asset on defense is catcher Sean Murphy, one of the best pitch framers in the game. His backup, Travis d’Arnaud, is no slouch either. This gives Strider more freedom to play in the shadow zone, where he induces a ton of chases and misses. The Cubs, on the other hand, boast one of the best infield defenses in the game, perfect for a groundball-heavy pitcher like Steele. His .223 BABIP on groundballs is 20 ticks below league average, but with gloves like Dansby Swanson, Nico Hoerner, and Nick Madrigal behind him, that’s no coincidence.

Steele and Strider have similar arsenals but totally dissimilar pitches. Those pitches lead to entirely different outcomes yet comparable overall results. Two pitchers, alike in dignity, but different as day and night. They may be different sizes, different ages, and, you know, two completely unrelated individuals, but all the same, Spencer Strider and Justin Steele are mirror image twins.