From Spencer Strider's curveball to Jung Hoo Lee's exit velocity, let’s find some meaning in spring training data

Spring training is, almost entirely, a bag of lies. A small-sample mirage shrouded in empty hope.

Besides the occasional gut-wrenching, catastrophic injury, spring exhibition games provide little in the way of the definitive, conclusive or predictive. That’s because nobody is playing to win in March. Hitters and pitchers are focused on getting themselves and their bodies ready for the six-month marathon to come. Outcomes during the six-week Arizona/Florida trudge are irrelevant. The Los Angeles Angels, for instance, have won the past two Cactus League “championships.”

But there is gold in the riverbed, riches hidden in the muck.

The advent of pitch and batted ball tracking technology means the public has access to reliable, objective data. Instead of evaluating a pitcher on how many strikeouts he tallied in camp, we can look at changes in fastball velocity or pitch mix. Hitters can be judged on the quality of their contact instead of something as comical as spring training batting average.

With that in mind, let’s sift through some data from the spring to find the potentially meaningful and lasting developments.

Spencer Strider is throwing a curveball

Strider laid waste to hitters last year, with an outrageous, league-leading 36.8 K% despite leaning on his fastball/slider combo a whopping 95% of the time. While he flashed an occasional plus changeup, Strider has been lacking a meaningful third pitch against lefty bats — until now.

He threw a curveball in college at Clemson but shelved it upon reaching pro ball. But in each of his two spring training outings thus far, the mustachioed flamethrower has shown multiple uncle charlies. The pitch isn’t a true 12-6, end-over-end breaker, and it features more side-to-side sweep than most curveballs, but it should give left-handed hitters something else to think about. This pitch is likely to survive the testing ground of spring, giving Strider another weapon against opposite-handed hitters.

Fantasy spin for 2024: Strider was arguably in a fantasy tier by himself already, so the addition of a possible plus third pitch could make him a top-three player. He’s the league’s clear best pitcher who should also benefit from elite run support, so Strider will rack up wins and is worth a top-10 pick. — Dalton Del Don

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Bryce Miller has added a splitter

Miller’s rookie year with the Mariners was solid, though unspectacular: a 4.32 ERA across 25 starts with under a strikeout per inning. And the 25-year-old’s handedness splits were outrageous: Right-handed hitters slugged just .315 against him (top 15 or so in MLB), while lefties crushed his soul to the tune of a .558 slugging percentage (second-worst in MLB).

To try to mitigate that imbalance, Miller added a splitter to his repertoire over the winter. The pitch is visually beautiful, but more importantly, it grades out extraordinarily well from a data perspective. Don’t expect Miller to throw the splitter a whole lot right away, but the downward movement of the pitch should give lefties fits and help him even out his performance.

Fantasy spin for 2024: Miller has a Yahoo ADP outside 200 and isn’t being drafted as a top-55 fantasy starter, so he’s an affordable arm to target. Miller can make a real leap in year two if his new splitter helps neutralize lefties. — Del Don

Hunter Greene debuted 2 new pitches

Greene took a step forward across the board in 2023 but was still too reliant on his fastball/slider combo, throwing that duo a Strider-esque 95% of the time. Even though Greene throws 100 mph, his fastball shape and lack of pinpoint command left him too dependent on swing-and-misses to get outs.

Enter two new pitches: a splitter and a curveball.

Unfortunately, the former No. 2 overall draft pick hasn’t thrown in a stadium with Statcast capabilities yet this spring, but eyewitness reports on both pitches have been positive. Greene’s athleticism and arm speed lend confidence that he’ll be able to incorporate at least one of the two offerings into his mix consistently.

“I want some complete games this year,” Greene told Charlie Goldsmith of the Cincinnati Enquirer. “All of those pitches need to be ready to go.”

Fantasy spin for 2024: Greene hasn’t struggled against left-handed batters throughout his career, but the addition of a third pitch certainly can’t hurt. He’s coming off an unlucky season in which his BABIP would’ve led all qualified starters, while his 3.74 SIERA would’ve ranked top-15. Greene has huge fantasy upside given his massive strikeout potential, so he looks like a steal being drafted as the SP37. — Del Don

Casey Mize and Tarik Skubal are throwing fuel

The pair of Tigers entered spring training on very different trajectories. Mize, the 2018 No. 1 overall draft pick, has endured a lengthy recovery from Tommy John surgery that has kept him off the diamond since April 2022. Skubal, on the other hand, was one of the game’s best hurlers over the last two months of 2023.

Fortunately for the Tigers, both have come out this spring throwing heat.

In a two-inning stint against the Yankees on Sunday, Mize sat 95.4 mph with his fastball, a tick and a half higher than the last time he was healthy. And according to Marquee’s Lance Brozdowski, the shape on Mize’s heater featured much more ride and carry than prior to his injury, a very good sign.

Skubal, meanwhile, was borderline untouchable Tuesday against the Red Sox. The 27-year-old southpaw averaged 97.4 on his four-seamer across three innings and touched 99. He threw seven changeups and got swing-and-misses on four of them! Sure, he was facing the underbelly of Boston’s spring training roster, but 14 whiffs in just three frames is outrageous stuff.

Fantasy spin for 2024: Mize is a deep fantasy sleeper who will move up draft boards if he continues to flash good stuff this spring. Skubal has Cy Young potential but is being drafted as the SP15 in Yahoo leagues. Wins could be an issue, but Skubal should be treated as a borderline top-five fantasy starter. — Del Don

Jung Hoo Lee showcased his power

Lee is one of MLB’s most fascinating mystery boxes heading into the season. After a half-decade of magnificence in Korea, the 25-year-old signed with the Giants over the winter on a six-year, $113 million deal. He has been billed as a complete, well-rounded, high-contact bat who could be a potential Gold Glove in center field. However, some doubted whether Lee could hit for sufficient power against MLB competition.

While nothing in February or March will definitively answer that question, Lee’s 109.7 mph exit velocity homer last week means he has, at the very least, MLB-average raw juice. José Altuve, Dansby Swanson and Bryson Stott are all productive big-league hitters who didn’t hit a ball that hard last season. Lee still needs to prove that he can (1) consistently hit balls that hard and (2) hit balls that hard in the air, but a 109.7 blast is a fantastic start for a player with the chance to become one of the league’s most captivating center fielders.

Fantasy spin for 2024: Lee could immediately hit .300 and be a big help to San Francisco, but he has a few obstacles to his fantasy value. The Giants’ lineup will hurt his counting stats, and Lee’s impressive spring home run would’ve left 29 of 30 major-league stadiums — the lone exception being in San Francisco. Lee will need to run more than expected to be a big fantasy contributor. — Del Don

J.T. Realmuto has upped his exit velocity

The Phillies catcher had an underwhelming offensive showing in 2023, at least by his lofty standards. So this offseason, Realmuto spent a significant amount of time at the team’s biomechanics lab in Florida with hitting coach Kevin Long. According to The Athletic’s Matt Gelb, the goal was to remove a gaping hole in Realmuto’s swing — he was getting diced up under his hands on the inner half — to get the three-time All-Star back to his swashbuckling best.

Last season, Realmuto put 357 balls in play. His highest exit velocity was 110.6. The fourth ball he put in play this spring — a rocket groundout to shortstop — was lasered at 110.8. Now, as the season gets rolling and the rugged realities of catching start to wear down Realmuto, there’s reason to expect his numbers to decline somewhat. But it’s certainly encouraging that at this point in the year, the data shows a rejuvenated version of Realmuto.

Fantasy spin for 2024: It's good to see Realmuto hitting the ball harder this spring, whether that’s a result of a mechanical change, improved health or both. The younger Adley Rutschman goes multiple rounds earlier in fantasy drafts, but some projection systems like Realmuto more, and that’s without accounting for the offseason work he put in. — Del Don