A Game Beyond Explanation
"...Every single move he's played so far has been a Blue Spot?"
A Blue Spot is never just one move. An AI engine offers three to five recommendations in any given position, and flags those with negligible differences in win rate as Blue Spots. Which meant Mumyeong had, through all thirty-one moves of the game so far, selected the precise Blue Spot at every single turn.
What on earth is happening right now?
Jang Yu-na, 2-dan, swallowed dryly. A thought flashed through her, unbidden.
...He's not cheating, is he?
No. She forced the idea away. What would Mumyeong even have to gain? With the skill he'd already shown, there was no reason for it.
"Everyone, it's still the opening, okay? You know how this works — AI match rates peak early and then drop off a cliff once the middlegame starts."
That much was true. There were games where the concordance sat near a hundred percent through the opening alone. The problem was that it was still happening. Right now.
Click.
Mumyeong's next move.
Blue Spot.
And the one after that.
Another Blue Spot...
Thirty-five moves in, and his match rate was still nothing short of miraculous. The chat began to stir.
"Cheating? Come on, everyone! He just... coincidentally, coincidentally hit them. You all know Mumyeong isn't that kind of person, right?"
Jang Yu-na forced a laugh, but inside she was burning black. They're going to slap a penalty on this stream, aren't they?
She couldn't sit still. Mumyeong was the channel's flagship content. True or not, even the rumor of an investigation would hit her hard.
Please. Just play like you always do.
Whether that desperate wish reached him or not — click. The move Mumyeong placed came up gray on the DeepStone display, not blue.
Jang Yu-na's eyes went wide. It was the kind of move that made you wonder if he'd simply put it in the wrong place.
A move unworthy of Mumyeong. A blunder that shattered the precise, AI-like reading he'd been displaying all game. Lu Yuan, 6-dan, did not miss the opening. He drove into the gap with relentless pressure and seized the initiative. The position tilted, and DeepStone's win rate began to lean, slowly but steadily, toward his opponent.
And through it all — gray. Then gray again. The flawless Go Mumyeong had been playing was collapsing as if it had all been a lie.
He's... he's going to lose like this?
Jang Yu-na caught her breath. Her throat had gone bone-dry from the tension, but she didn't even have time to reach for water.
"You have to focus, Mumyeong! It's still early middlegame — there are plenty of places left to turn this around!"
Whether it was encouragement or a prayer, Jang Yu-na couldn't have said.
Then — click. A Blue Spot again. And another, dead on.
Hope flared in Jang Yu-na's eyes. Is he going to flip it?
Click. A gray spot, betraying every bit of that hope.
Ah.
Expectation and disappointment crashed into each other.
Somewhere in the middle of all that, the game crossed into the middlegame.
Wait... wait.
All at once, the moves that were uniquely Mumyeong's began to flow — moves more Blue Spot than a Blue Spot. The kind of choking, suffocating pressure that only a human being could feel. And then the last decisive battleground arrived. Lu Yuan, outread, produced a string of losing moves, and the position flipped.
DeepStone's win rate: Mumyeong 50.7 percent. Lu Yuan 49.3 percent.
The final endgame. Lu Yuan hunted for a reversal, but Mumyeong gave him nothing. The count came in.
"He... he won by half a point."
Jang Yu-na's face was dazed. This had been a game possessed. Blue Spot. Blunder. Blue Spot. Blunder. And at the end, a single instinctive move that fell outside DeepStone's predicted range. Mumyeong had broken the flow with that one stone, wrenched the game sideways, and won.
The chat ignited. Jang Yu-na, who had forgotten she was supposed to be commentating and had been staring at the monitor the entire time, muttered under her breath.
"Holy... that's insane. That's actually insane. This is..."
She pushed her hair back with one hand. She'd seen it with her own eyes and still couldn't believe it. Swept along as if by a current, Mumyeong had completed a miraculous comeback.
Jang Yu-na couldn't find words for a long time. She stared blankly at the monitor, and then, very quietly, as if talking to herself, she spoke.
The precision of AI calculation. The intuition of a human being. A hybrid game that seemed to blend the two with uncanny delicacy. Unstable as it was, she felt she understood, just a little, what kind of Go he was chasing.
"Mumyeong... this person."
Jang Yu-na drew a quiet breath. One thing was certain.
And then she swallowed the last words. They weren't something she could say on stream.
...He's just a madman.
"Hah. That was close."
A half-point win. I checked the result, then washed my face with cold water. The moment I sank back into the chair, the tension drained out of me all at once.
This game had been an experiment — an attempt to understand AI moves. Hunt the Blue Spots. Play a style grounded in precise positional judgment.
"Let's review it."
I launched DeepStone from the desktop and compared the AI's recommended moves against my own, one stone at a time. The beginning had been fine. But once we entered the early middlegame, I started to wobble. The position grew complicated, the reading stretched long, and every time I tried to play like an AI, my instincts fell behind. Blunders detonated one after another, and the win rate hit rock bottom.
"Now I get why even the pros' AI match rates fall off a cliff from the middlegame on..."
From the middlegame onward, I'd gone back to my own Go. That was how I'd patched the collapsing position back together and, by a thread, manufactured the reversal in the endgame. Even that had only been possible because Lu Yuan had strung together losing moves. It felt less like winning a game than like barely dragging one across the finish line.
"Still... I learned something."
Go built on precise positional judgment. It was hard. It was the opposite grain of my own style. And that was exactly why it taught me more.
The opening, and the endgame.
Since I'd started studying with the AI, my strength in those two areas had clearly risen. Openings that used to slip away from me now flowed on even terms, and my endgame had become far more precise than before. That wasn't amateur-level proof — it was a result I'd demonstrated against a high-ranking professional from the Chinese Weiqi Association.
"Let's see. This one I played well. This move is a complete howler. In a spot like this, trusting my own instinct is the right call."
The boundary between AI moves and instinct. I needed to draw that line clearly. I worked back through the game one stone at a time, tracing the places where I'd come apart. It hadn't been a loss, but the middlegame wobble had been close enough to failure. Even so — this was exactly the kind of Go that pushed me further forward.
And then, at the edge of my vision, a system window flickered into being.
"...!"
My heart dropped once, hard. It was the message I had been waiting for.
This is it.
My goal was never simply to become a professional. If that had been enough, I wouldn't have started at all. I would have stayed an amateur and chased prize money. I wanted to compete with the best players in the world — and beat them.
World-class players are strong.
I was strong now, too. But I wasn't overwhelming. They had already gone beyond what I understood as common sense. The world title finals I'd been watching on YouTube lately — the dazzling reading, the board architecture honed against AI, the brilliant moves that flipped a game at the decisive point. I would collide with those people from the Ciel Bank Cup integrated preliminaries onward. If I wanted certain victory, I needed the evolution. And right now, I was standing at the edge of that threshold.
Bzzzt.
"Huh?"
The phone I'd left on the desk buzzed. A message from Yuzuha.
I looked down at the phone in silence. I hesitated for a moment — but there was no reason to. If I wanted to get through the Ciel Bank Cup integrated preliminaries and punch into the main event, I needed this. I sent the reply immediately.
Inside the bank branch, ten minutes before opening. With the Branch Manager away on a business trip, the Deputy Branch Manager ran the morning briefing in his place.
"In-ha's on leave all next week, so keep that in mind. When the temp comes in, Assistant Section Chief Ha will handle the handover."
The Deputy Branch Manager was a man of few words. The briefing ended just as simply, with nothing extra.
"That's all. Everyone get to work."
He returned to his seat. I was about to peel away toward the desk when a voice stopped me.
"In-ha."
Section Chief Park, who oversaw withdrawals and ATM operations, had called me over. Assistant Section Chief Ha stood beside him, looking thoroughly displeased.
"If you're going to take leave, Assistant Manager Kim, you could at least give us a heads-up. What are we supposed to do if you vanish for an entire week?"
Park went on, a sigh mixed into his voice.
"You know as well as I do that ATM work isn't easy to hand over, even with a temp coming in."
Ha, standing at his elbow, jumped in as if he'd been waiting for his cue.
"I heard you're going to some Go tournament or whatever. Still — springing it on us like this is a bit much. There's such a thing as consideration."
Ha.
For a moment I was too incredulous to speak. They both came at me as if they'd been saving it up. Come to think of it, Yeon-hui had mentioned it in passing — ever since the Branch Manager had ordered that the bank security guard not be assigned any other work, the withdrawal team's ATM load had gone up. But that had never been my job in the first place.
Am I really supposed to just swallow this?
Before, I would have said "I'm sorry" and let it go. Even though I hadn't done anything wrong. Back then I'd thought that if I just endured it, that would be enough. Like an idiot.
"Assistant Section Chief."
My voice came out low and even. Strangely, my head was cold and clear.
"I used annual leave that is legally guaranteed to me."
"I know that, I know, but—"
"This is my right."
I cut him off, clean.
I looked steadily at Section Chief Park and Assistant Section Chief Ha. Apparently they hadn't expected me to come back at them like this; both of them looked openly flustered.
"No, Assistant Manager Kim, what I meant was—"
"And I'm a contract worker. When I take leave, it comes out of my own paycheck."
"..."
"I'm the one absorbing that cost. I don't think anyone else gets a say in it."
Silence. The air settled in a strange, heavy way. Everyone was watching for cues; no one opened their mouth.
Ah.
It was a feeling I had never had before — like a blockage I'd been carrying for years had finally broken open. A sharp, electric satisfaction.
I should have said this a long time ago.
This much was fine to say. No — this much was something I should have said. It had been a legitimate demand.
That was when Yeon-hui, who had been quietly watching the whole thing, glanced down at her phone and spoke up.
"Oh? There's an article about Assistant Manager Kim here, too."
Ha's head snapped around. The other employees' eyes swung toward Yeon-hui as well.
"Wow. How many titles is this? Presidential Cup champion, Sudam Cup champion, Namwon Chunhyang Cup champion... the prize money alone has to be over ten million won, right?"
Yeon-hui made her eyes go wide, putting on a look of exaggerated astonishment.
"And this one looks like the tournament he's heading to now... the winner's prize is three hundred million? Three hundred million won?"
Her over-the-top performance had the rest of the staff looking stunned. A few of them glanced at me as if to ask whether it was actually true. And Section Chief Park and Assistant Section Chief Ha's faces twisted as if they'd bitten into something rotten.
"The article says that even just getting through the preliminaries makes turning pro look likely?"
I had to clamp down on a laugh that nearly escaped. Yeon-hui, that little fox. How was she this good at acting?
"Assistant Manager Kim, be honest with us. Go is your real job, and the bank security gig is just a side hustle, right?"