18: The Death Formula of a Mathematical Genius

At 1:17 AM, Cheng Mo's fingers hovered over the keyboard for three seconds before gently pressing Enter. On the screen, the refresh animation of the financial dashboard completed its final spin, and the data settled: 63 concurrent online users, average heartbeat 89, crash index 4.3—everything was running as smoothly as a perfectly calibrated vending machine.

He leaned back, the chair protesting with a creak. The dark circles under his eyes were so deep they looked like two lumps of clay stuck to his skin. The silver stud in his right ear glinted once in the screen's light. His water cup had long been empty, a ring of tea stains at the bottom crooked and twisted like a forgotten Easter egg hint.

He didn't go to refill it.

His fingers slid the mouse, clicking open the permanently pinned browser tab—the official forum for 'leap platform nightmare.' The page loaded, the homepage featuring a screenshot of Steel Coin throwing his keyboard during yesterday's livestream as the header image. Below, the hot posts were all variations of 'This level is impossible,' 'The developer is mentally twisted,' and 'Recommend sending him to a psychiatric hospital for clinical research.'

Cheng Mo scrolled down post by post, the corner of his mouth twitching. The harsher the insults, the more stable the servers ran—a principle he now understood better than anyone. He even felt like sending a private thank-you message to certain usernames. After all, the sight of them cursing while simultaneously spending money was like someone handing you the stick they were being beaten with.

Until, on page 17, he saw a title: 'Abnormal Observations Regarding the Acceleration of Falling from the Leap Platform.'

Poster: Math Genius

Post Time: 00:48

Replies: 0

The content was just one line: 'The gravity formula is missing a squared term.'

Cheng Mo stared at that sentence for five seconds, his fingers suddenly freezing. He blinked, pulled the page closer, and read it again.

"...Huh?"

He let out a soft laugh, thinking it was some physics major student, unable to sleep in the middle of the night, engaging in performance art. He'd seen plenty of posts like this—people using differential equations to derive the comfort zone for jumping feel, others applying chaos theory to analyze the rhythm of failure sound effects. More entertaining than practical, but at least it showed players were genuinely puzzling over the game.

But this time was different.

He sat up straight, ignoring his hoodie's hood slipping off his shoulders. He clicked into the source code editor, navigating through the path: `/engine/physics/core_update.cpp`. The file opened, and he scrolled the cursor to the physics engine module. He knew where the gravity calculation was; after all, he had adapted it from a university textbook formula he'd copied. The original was the free-fall displacement formula. He'd changed it to `position += velocity * dt + gravity * dt;`—thinking at the time that missing a square made it feel more 'floaty' and weird, which happened to suit the game's vibe.

He had never thought to verify if it was correct.

Now, he created a new local test scene, input ten sets of jump parameters with different initial velocities, and let the simulator run continuously. The first six sets of curves could still roughly fit the theoretical trajectory. Starting from the seventh, the landing points noticeably deviated. By the tenth set, the character, which should have landed on the platform's edge, clipped straight through the model and fell into the void.

"Fuck," he muttered under his breath.

It wasn't a latency issue, nor a rendering error. The calculation itself was wrong. The difference between `g*t` and `g*t²` wasn't just a coefficient; it was the entire squared growth relationship across the time dimension. It wasn't noticeable in short bursts, but once a player played continuously for two hours, the cumulative error would snowball, eventually causing the collision detection system to completely fail.

He traced the variable chain backward, checking layer by layer, until the cursor finally stopped on line 372:

```cpp

acceleration += gravity * delta_time;

```

It should have been written as:

```cpp

acceleration += gravity * delta_time * delta_time;

```

Or, more standardly, to handle the gravity term independently, calculated outside the integration. But written as it was now, it treated uniformly accelerated motion as uniform motion—a pure rookie mistake.

Cheng Mo stared at the screen, unconsciously spinning a pen between his fingers. The pen tip had long broken off, leaving only half a plastic barrel rolling back and forth. He remembered the three validation rules he'd disabled during development—the unit tests threw too many errors, and he'd found them annoying, so he simply commented them out. Back then, he'd told himself he was 'pursuing the right feel.' Now, it looked like pure arrogance.

He exited the simulator, switched to the backend logging system, and searched for the user ID 'Math Genius.'

The records popped up:

- Total playtime: 14.7 hours

- Submitted bug reports: 9

- 3 of which were marked as 'high priority'

- Earliest login time: 43 minutes after the game launched

This person wasn't guessing randomly. They had physically collided with the conclusion, jumping over and over, recording data each time, finally calculating the mismatch between theoretical and actual values, and reverse-engineering the formula flaw.

Cheng Mo pulled out a pad of scratch paper, tore off a sheet, picked up a pen, and started writing out equations.

First line: s = v₀t + ½gt²

Second line: Current code implements s ≈ v₀t + gt·Δt

Third line expanded the error function, plotting the deviation curve growing over time... He filled three pages. With the final stroke, he heavily circled the erroneous term and stopped. He stared at that red circle for two seconds, then suddenly crumpled the entire stack of paper into a ball and flung it into the trash can. The ball hit the side of the bin, bounced, rolled next to the server's heat vent, almost getting sucked in.

He didn't pick it up.

He opened the development log document and wrote under the latest entry:

`v1.03.07 — Acknowledgments to player 'Math Genius' for correcting a fatal flaw in the physics engine. Remember: The real testing always happens after release.`

After typing, he leaned back in his chair, resting his right hand on the edge of the keyboard, his fingertips lightly tapping three times—the exact same rhythm as before. Not a celebration, nor anxiety. More like confirming if the tactile feel of a certain key was still there.

On the other side of the screen, the 'leap platform nightmare' servers continued to run smoothly. 63 players were online, 7 of them marked with yellow IDs, belonging to the 'Pain Knight Candidates.' Their operation logs kept uploading, each frame exposing new boundary vulnerabilities.

Cheng Mo looked at line 372 of the code. The cursor was still blinking there, like a needle refusing to shut up.

He didn't fix it.

Not because he didn't want to, but because he couldn't push an update immediately. The last hotfix had triggered Steam's caching mechanism, causing over two thousand players' clients to crash. The system was still on the blacklist. Forcing a push now would be actively creating an incident.

He could only wait—for the next version review window, for the system's automatic scheduling. Until then, the game would continue running with the error, and players would keep jumping, failing, raging, and trying again in a flawed physics world.

And the person called 'Math Genius' had already logged off. The last login time was 00:51, with a session duration of 13 minutes. No follow-up message, no screenshots, no bragging. They left right after posting that one line.

Cheng Mo closed the log page and reopened the forum. He clicked into 'Math Genius's' profile page. All he could see was the registration date, post history, and level Lv.3. No signature or personal statement.

He thought for a moment, moved the mouse to the reply box, and typed three characters: 'Understood.'

Deleted.

Typed again: 'Will fix.'

Deleted.

In the end, he didn't post anything. He just added that post to his bookmarks, categorizing it under 'People I Must Live to Meet.'

Outside, dawn was approaching. The first sound of a cleaner's cart came from the hallway, and in the distance, an early morning bus started its engine with a rumble. The fluorescent light in the basement was still on, casting a cold gleam on the lockbox atop the safe. The tea stain at the bottom of the empty cup on the desk corner had started to dry and crack around the edges.

Cheng Mo reached out, picked up the broken pen, and lightly scratched it against the casing of the code editor, producing a faint scraping sound. His eyes remained fixed on the screen, on that unmodified line of formula, as if staring at a grave he had dug with his own hands.