Korean Chipper Jones

"Yoo Seonghyun."

"Yes, Manager."

"Quite a few fans have turned up to see you today. You're out of the starting lineup as planned, but how would you feel about pinch-hitting in the late innings?"

"Ah."

Had his explosive performance during the exhibition games left that deep of an impression? Or was it simply because there were no First Team games scheduled on a Monday? Whatever the reason, spectators ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠had actually made the trek out here for a mere second-team match.

This was Gimhae Stadium, home of the Busan ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Titans' second team. Tucked away deep in the foothills, the facility was notoriously difficult to reach by public transit, with the nearest bus stop requiring a steep thirty-minute hike. Yet the tiny grandstand behind home plate—barely five hundred seats in total—was packed nearly to capacity. It was the premier vantage point in any ballpark, offering an unvarnished view of the diamond alongside the sharp, echoing pop of the catcher's mitt.

The gap in infrastructure between the leagues was glaring. In the United States, a Triple-A ballpark routinely accommodated ten thousand spectators, while here, the facility capped out at a modest five hundred.

"I wouldn't mind starting either, sir," Seonghyun said.

"Is that so? Well, we can't alter the submitted lineup card now, so let's have you step in to pinch-hit around the middle innings."

"Understood. Would it be all right if I spend an hour finishing up my conditioning before heading out to the dugout? First pitch is at one o'clock, correct?"

"Do whatever suits you best. Just make sure you're out there by one."

"Yes, sir."

Approximately two months remained until he became eligible for a First Team call-up on June 1st. For that reason, Seonghyun's current regimen prioritized flexibility, core stability, and kinetic balance over heavy lifting.

Having committed to switch-hitting in this lifetime, preserving dynamic balance demanded meticulous care. His swing mechanics from both sides of the plate were already dialed in; packing on surplus muscle mass now carried the dangerous risk of throwing off that delicate kinetic chain. The only persistent annoyance was his frame—he was still growing.

Please, just stop growing already...

His daily routine relied on modest maintenance weights supplemented by intensive yoga and pilates sessions. During breaks, he spent his downtime analyzing First Team game tape and diving into sabermetric data.

Back in 2028, the KBO had fully integrated Statcast, mirroring Major League Baseball's comprehensive player and game-tracking tracking systems. Baseball, above all else, was a game of numbers. Because every play unfolded within strictly defined parameters—a pitcher throwing to a batter in a stationary box—the sport offered an unprecedented wealth of quantifiable metrics.

What had begun with rudimentary figures like pitch velocity and hit distance had evolved under the banner of sabermetrics, dissecting the sport beneath a high-powered microscope. In his past life, Seonghyun had been a devout disciple of the discipline—a dyed-in-the-wool sabermetrician. At the end of the day, even if fallible human beings played the game, data never lied. It was pure sports science.

How players received such data varied wildly, of course. But for someone like Leon, who had done everything legally within his power to survive and thrive at the pinnacle of Major League Baseball in his previous existence, objective analytics had proven indispensable.

Just last Saturday, while Seonghyun was reviewing sabermetric spreadsheets in the facility's PC lounge, Park Jaehyung had wandered in and peered over his shoulder.

"What're you doing?"

"Oh. Hey, Jaehyung."

"What on earth are you staring at? I've never seen you play a single video game since we got here."

"Sabermetrics."

"Saber-what now?"

"...Haaah." Seonghyun rubbed his temples. That an idiot like this was trusted to strap on catcher's gear felt like a grim harbinger of the end times.

To begin with, having a dedicated PC bang inside a minor-league training complex was absurd enough. A billiard hall, a karaoke booth... the rookies here were thoroughly spoiled. Did athletes need appropriate rest? Naturally. But why on earth did a developmental facility need internet cafes, pool tables, and singing rooms?

Kids these days... Tsk, tsk. Supposed to be professional ballplayers...

"Look closely," Seonghyun said, pointing at the monitor. "These are quantified metrics for offensive production. Set exit distance aside for a second. Hot and cold zones, exit velocity, launch angle, bat speed, whiff rate, contact percentage, hard-hit rate, barrel rate, zone swing percentage, chase rate... Hey, where are you going?"

"Gotta hit the restroom real quick."

"Hold it and listen. If you actually learn to read these numbers, you might find a ticket to the First Team yourself."

"...Me?" Jaehyung blinked.

"You know our starting catcher got permanently banned from the league after that fatal drunk-driving incident, right?"

"Yeah, obviously."

"And who is catching for the First Team right now?"

"Senior Lee Mingyun?"

"Exactly. Now look at Senior Lee Mingyun's numbers. It's still an early-season small sample, but his traditional batting average is lingering in the high .100s. Even if his disciplined chase rate props up his on-base percentage, his overall OPS is stuck in the mid-.500s. He's crashed headfirst into the aging curve."

"Ah... Senior..."

"He was supposed to transition into a playing-coach role this season, serving as a late-inning defensive replacement. Instead, he's being forced to shoulder everyday starter duties. Do you understand what that means? An opportunity is opening up. Which means you need to show out in Monday's second-team game."

"Doesn't the First Team still have an active backup catcher, though?"

"They can't trust him defensively, so he's riding the pine. Looking at last year's tracking data, his PASS/9 was 0.612. That's borderline unplayable. Did you not watch him bobble balls throughout spring training and exhibition games?"

"What kind of metric is PASS-whatever anyway?"

"Haah..." Seonghyun let out a heavy breath.

The faint shred of confidence he had built toward the Titans' scouting department—spurred by their sharp foreign acquisitions of Lucas, Alberto, and Luis—instantly evaporated. Why had they handed this dunce a signing bonus? Granted, the previous draft had been universally panned as a historic bust outside of the consensus number-one overall pitcher. But still, drafting a backstop who didn't know basic sabermetrics?

"PASS/9 measures the combined total of passed balls and wild pitches per nine innings," Seonghyun explained, speaking slowly as if addressing a toddler. "Anything above 0.5 is alarming, and he's sitting at over 0.6. Granted, our First Team staff—especially the righties—rely heavily on splitters in the dirt, which naturally inflates the metric. But even factoring that in, his numbers are atrocious. Do you get it now? On top of that, his caught-stealing rate barely clears ten percent."

"Was Senior Lee Mingyun good back in his prime?"

"In his peak years, his PASS/9 hovered in the low 0.3s, which was elite, and his caught-stealing rate sat comfortably in the mid-twenties. He was the textbook definition of a glove-first defensive catcher. Offensively, he contributed a .250 average, an eight-percent walk rate, and an OPS around .700. For a demanding defensive position like catcher, that made him an invaluable regular."

"...Wait, how the hell do you have all those numbers memorized?"

"I'm giving you serious advice here. If you want to put food on your table playing baseball, this is the bare minimum you need to know."

"...Hmm."

A professional catcher ought to at least memorize opposing hitters' hot and cold zones. And that was just ground-floor knowledge; whiff percentages, batting averages by pitch type, spray charts—the list of variables was endless. Seonghyun shook his head.

"Anyway, you're starting behind the plate on Monday, right?"

"Yeah. Why?"

"Follow me. We're firing up the Traject Arc so I can run you through framing drills and clean up your swing mechanics."

"Wait, I literally just finished training—"

"Don't bother if you don't want to. Your First Team call-up will just get delayed that much longer. Besides, Monday's starting pitcher for Sangmu has First Team tracking data on file, meaning we can replicate his exact repertoire on the Traject Arc."

"Who said I didn't want to?!" Jaehyung blurted, bolting to his feet.

Seonghyun smirked faintly. Ever since elementary school, this guy has been predictable to a fault.

The Sangmu Phoenix.

Operated under the umbrella of the Korea Armed Forces Athletic Corps, Sangmu functioned as a military baseball club where professional ballplayers fulfilled their mandatory service while continuing to play competitively. Their moniker in the minor circuit spoke for itself: the Rulers of the Futures League.

Nearly the entire roster consisted of established First Team regulars fulfilling their military duty or blue-chip prospects handpicked from farm systems across the nation. In the minor league hierarchy, Sangmu reigned as an absolute juggernaut. Competing in the Southern division of the Futures League, their staggering streak of fifteen consecutive division titles stood as undeniable proof of their supremacy.

Because Sangmu was such a formidable opponent, the coaching staff had originally slated Seonghyun to start tomorrow and the day after, when their ace starters were scheduled to pitch. Today, however, with so many fans braving the journey on a quiet Monday afternoon, the manager had agreed to insert him into the heart of the action as a mid-game pinch hitter.

"Phew..."

"Nervous?" Seonghyun asked, glancing sideways.

"W-Who's nervous?!"

"If you're freezing up here, how do you expect to lead the Titans to a championship? Weren't you the one bragging that you'd deliver a trophy with your own two hands?"

"Ahem!" Jaehyung coughed violently, his ears flushing scarlet.

Leaning against the dugout railing, Seonghyun teased the fidgeting catcher while tracking the opposing starter's warm-up tosses on the mound. Lee Seonho. Twenty-two years old, standing 188 centimeters and weighing 95 kilograms—a right-handed three-quarters arm.

Originally drafted by the Daejeon Hawks, Lee had earned spot starts and long-relief assignments in the First Team. Having narrowly missed out on a national team exemption, he had enlisted with Sangmu and slotted directly into their starting ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠rotation beginning last year.

His career First Team numbers sat at 22 appearances across 85 innings, an ERA of 4.21, a WHIP of 1.71, a strikeout rate of 9.11 K/9, and a walk rate of 5.12 BB/9.

His blistering velocity and heavy pitch life generated strikeouts in bunches, but command remained his glaring Achilles' heel. A WHIP approaching 1.8 paired with over five walks per nine innings painted an unmistakable portrait of erratic control.

In the Futures League, however, he was treated as an unhittable ace. When an arm could pump four-seamers up to 152 km/h spinning at 2,400 RPM right down the heart of the plate, minor league hitters simply lacked the bat speed to catch up.

I don't know exactly what inning they'll call my number, Seonghyun thought, a predator's grin tugging at his lips, but stepping into the box against him should be fun.

A spin rate of 2,400 RPM on a heater meant tremendous ride through the zone. Hitting against fastballs with that kind of life was always a treat—the heavy, solid shock reverberating through the barrel into the palms was one of the finest feelings in baseball.