The Woman Who Never Gives Up
The sudden self-praise from Xiahou Ying caught me off guard. Yet it didn’t take me long to grasp the true meaning behind his unexpected words.
‘Like that Michael Jordan from the UNC geography department…’
Xiahou Ying. The man destined to become Liu Bang’s personal charioteer and, in the future, the Taifu who would lead chariot units across the empire. His horsemanship was a clear outlier. A single dot plotted far beyond the curve—the statistical trap, the exception at the edge of the graph. Having reached the realm of perfect unity between rider and horse, he had unconsciously been compensating for the prototype’s flaws. When his foot slipped, he twisted his ankle to correct it. When it rattled, he absorbed the shock with his hips. All of it half by instinct.
‘Well… there was no way a stirrup I slapped together without even knowing how to ride properly—let alone understanding what a stirrup actually was—would be perfect from the start.’
The first tester had been exceptionally skilled. That very excellence had masked the device’s fatal defects. It was a failure pattern I’d seen countless times in modern product development.
Survivorship bias.
By only studying the success stories of experts, people assume a product anyone can use, when in reality it’s nearly impossible for beginners. I had fallen neatly into that sweet trap.
“……I understand what you mean, Lord Xiahou.”
I let out a deep sigh and covered my face with both hands.
“In other words, you were adjusting the stirrup’s discomfort in real time.”
“Yes. At the time, I judged that anyone could make adjustments of that level, so I didn’t report it separately.”
Xiahou Ying rubbed his nose, looking somewhat embarrassed.
“Indeed. Xiahou is, without question, an outstanding rider who can control a horse even without a saddle.”
Xiao He nodded in agreement. Cao Shen remained silent, simply watching me with steady eyes.
‘Then… what now?’
Any further engineering improvements were beyond my knowledge. After all, I was just an ordinary liberal-arts graduate who used to work at a company.
As I pondered a solution, Xiahou Ying bent one knee and met my gaze directly.
“Sister-in-law. There’s no need to look so discouraged.”
“……”
I stared at him wordlessly. His expression grew more serious as he continued.
“The stirrup is a magnificent invention. I guarantee it. It simply requires a bit more refinement right now.”
Xiahou Ying walked over to the red bag, loosened the stirrup, and held it up.
“First, regarding the foot slippage that Lord Cao pointed out—if we wrap something around the inside, wouldn’t that solve it? Something like leather or hemp cord to prevent slipping.”
“……Please go on.”
“As for the size issue…”
Xiahou Ying shook the stirrup up and down as if weighing it.
“Wouldn’t it be simple to just make several different kinds?”
“……”
Making several different kinds. In other words, creating size variations for different people.
‘But in this era, something like custom orders…’
That was impossible. No matter how much money you had, the number of blacksmiths capable of working iron freely was extremely limited. Of course, making stirrups from wood, leather, or bronze was an option, but then durability became the problem. To maintain consistent combat effectiveness in the brutal environment of the battlefield, I wanted the frame to be made of iron.
‘In that case…’
I thought for a moment. My mind drifted back to shoe stores from my previous life.
‘……Standardization?’
My eyes widened.
‘Small, medium, large. Create three broad categories. Then supply leather overshoes or straps that can be inserted into the stirrup to fine-tune the fit.’
Eureka. In simple terms, make the stirrups generously sized and use insoles inside to adjust the details.
“And regarding the height of the stirrup straps, we can gather opinions from many people and find the optimal height. If we set only a basic height, riders can adjust the straps afterward according to their own preference.”
“Yes. We could also consider drilling holes throughout the entire strap for size adjustment.”
Like a modern belt, I supposed.
“Excellent. Then let’s begin the improvements with that approach.”
I lifted my head again. Yes. Giving up here wasn’t like Lü Zhi at all. Once you identify a problem, offering a solution is what professionals do.
“Lord Xiahou.”
“Yes, Sister-in-law.”
“May I ask you one question?”
“Ask me anything.”
“Lord Cao said the balance of the seat collapses. Because force is applied through the feet, the hips lift and the upper body shakes, making it impossible to give the horse the delicate commands it needs. How should we solve this?”
“Hmm… for that…”
Xiahou Ying glanced briefly toward Cao Shen. Cao Shen simply shrugged as if to say, Let’s hear it.
Xiahou Ying turned back to me and spoke again.
“That is probably a matter of usage.”
“Usage?”
“A stirrup is not something you keep your weight planted in constantly. You must flexibly shift your weight in accordance with the horse’s movement—like riding a wave. On flat ground, use your hips. When galloping, use your toes. Even when giving commands to the horse, you need to precisely change your center of gravity.”
Xiahou Ying gently stroked the stirrup in his hand.
“I was doing it unconsciously, but it will probably feel somewhat unfamiliar to riders accustomed to gripping tightly with their thighs to control the horse and balancing with grip strength. They will need to freely shift the center of weight they’ve always placed in their thighs down toward their legs.”
“In other words, training is required.”
“Yes. An ordinary person will need a certain amount of practice to handle stirrups properly.”
“……I see.”
At last, a rough outline was beginning to take shape. The stirrup was indeed a revolutionary invention. But that didn’t make it a magical tool. Proper training was necessary to use it correctly. And the hardware itself would need continuous, user-friendly improvements.
“Lord Xiahou.”
“Yes, Sister-in-law.”
“Could you organize a stirrup training methodology for me?”
“A training methodology?”
“Yes. For starters, something like guidelines aimed at people who already have experience riding horses.”
“Guidelines… Yes, I’ll think about it.”
Xiahou Ying nodded vigorously. I then turned to Xiao He.
“And Lord Xiao, I would like to request an investigation from you.”
“What kind of investigation?”
“The foot sizes of one hundred young men collected evenly from various villages. I plan to use that as the foundation for the design.”
It was standardization through random sampling. I would analyze the data to establish an approximate average, then set the small, medium, and large sizes based on that average.
“I would also be grateful if you could measure the length of their thighs and calves. I want to use that to determine the approximate position of the straps.”
After all, the first thing people do when getting into a car is adjust the seat position. Now was the time to add details for user convenience.
“And finally, Lord Cao, I would appreciate it if you could secretly gather those skilled with horses.”
“You mean to gather them from among the district officials and village heads.”
“Yes. Even so, those gentlemen should at least be capable of basic horsemanship.”
It was easy to think of cavalry as the exclusive domain of nobles, but in this era, cavalry was mainly an auxiliary branch handled by low-ranking officials like district clerks. After all, there was the clearly superior class of chariot troops. I would actively gather feedback from them and verify the usefulness of the techniques Xiahou Ying would come up with.
“Understood. I’ll select some.”
Cao Shen answered first. Xiahou Ying and Xiao He nodded as well.
“Thank you. I’ll be counting on you.”
Only then did I finally relax and bow my head politely.
Starting the very next day, I began work on improving the stirrup.
The first task was the slippage problem. The solution was surprisingly simple: friction. All I had to do was borrow the principle behind 21st-century tires. I planned to wrap the footrest portion of the stirrup with rough leather and make small cuts on the surface to increase friction.
“Masters, can you make this according to the explanation?”
In the workshop at Jeonunchang, I held out the blueprints I had drawn overnight to the gathered blacksmiths. They stared intently at my drawings, then each stroked their beards and let out a thoughtful “Hmmm.”
“So you want to put a leather coat on the iron hook.”
“Yes. To hold the foot firmly so it doesn’t slip.”
“Well, it doesn’t look difficult. The design is simple.”
“Then I’ll leave it to you. Ah, and I’d like to make them in three sizes. Is that possible?”
“Three sizes?”
“Yes. I plan to divide people’s foot sizes into three broad categories so they can choose the one that fits their feet. I’ll provide the exact specifications this afternoon.”
I nodded and added, “For now, we’ll make prototypes here, then soon entrust mass production to the young blacksmiths in the village. Please make them as simple and standardized as possible so that even those with less skill can follow along.”
“Standardization, huh… All right, we’ll give it a try.”
The craftsmen nodded lightly, as if it were nothing at all.
……Next came the training program.
“First, we train using ropes instead of stirrups.”
In the courtyard of Jeonunchang, Xiahou Ying drew on the ground with a tree branch as he explained.
“Shifting your weight in accordance with the horse’s movement. That is the core of using stirrups. To achieve that, we use ropes to learn the sensation of flexibly using the knees.”
“I see.”
“Next is practicing with only one foot in the stirrup. Like slowly preparing your body when stepping into cold water.”
“And after that?”
“Naturally, practicing with both feet. Of course, we’ll start by walking to get used to the sensation, then begin running once they’re familiar. I’m thinking of setting the period at about ten days.”
“A step-by-step approach.”
“Yes. Above all, the most important thing is not getting injured. If Lord Cao had slowly conditioned his body, I’m sure he would have been able to move much more smoothly.”
“In other words, you’re saying I was too impatient?”
“Ah, no! It’s not your fault, Sister-in-law. It was my mistake for thinking only from my own standards.”
Xiahou Ying jumped in surprise and hurriedly bowed his head.
‘It was a joke, but he reacted that strongly.’
Anyway, he really was a good kid. I smiled lightly and changed the subject.
“Lord Xiahou.”
“Yes, Sister-in-law.”
“While we’re at it, could you write down this training methodology? For the sake of teaching many people in the future.”
“Writing… But I’m terrible with characters…”
“I’ll write it. If you explain it verbally, I’ll translate it into easy-to-understand language and organize it.”
Fortunately, I was a former company employee who had written quite a few reports in my previous life. Thanks to Lü Zhi’s body, my handwriting was rather pretty too.
“Ah, yes. That should be fine then.”
Xiahou Ying nodded obediently. Before making the manual, we first began discussing the points that required caution.
……Next was Xiao He.
Three days later, in the morning, I received a summons from Xiao He and visited the office where he worked.
“Here are the records you requested, Madam.”
He handed me a thick bundle of bamboo slips with a bright smile.
“Ah, and while conducting the survey, I realized something.”
“What is it?”
“The reason you asked me to gather men evenly from each village. You wanted this survey to represent all the men of this country, didn’t you?”
“……Ah.”
A chill ran down my spine. This man had figured out the concept of sampling—the flower of statistics—all on his own.
‘Should I really not teach Xiao He any more future knowledge?’
I had felt it ever since I taught him double-entry bookkeeping, but for an ancient person, Xiao He had astonishingly flexible and logical thinking. I forced my expression back into place and smiled brightly.
“Yes, exactly. Right now the stirrups are only for the men of Peixian, but in the future they will be used by men across the empire.”
“Indeed. Your vision is truly exceptional.”
Perhaps thanks to everything I had done so far, Xiao He didn’t seem to harbor any strange suspicions about me.
‘I was going to teach Xiao He the concept of standard deviation while I was at it… but I’d better hold off for now.’
I let out a mental sigh of relief and carefully gathered the bamboo slips Xiao He had given me as if they were treasures.
……Finally, it was Cao Shen’s turn.
I visited the prison in the government office where Cao Shen worked, something I hadn’t done in a while.
“The personnel you requested are gathering smoothly. When they heard it was to help you, Madam, they were all full of enthusiasm.”
Cao Shen reported in a calm voice and served me tea. I carefully took the teacup and nodded.
“That’s good to hear. The prototypes will be completed within two days, so please prepare so we can begin training.”
“Yes, I will do so.”
Cao Shen nodded without asking any further questions. After that, a heavy silence settled between us.
‘This man really is a bit scary…’
The tension made the back of my neck stiffen for no reason. I sipped my tea and watched his expression.
How much time passed like that? At last, his tightly closed lips opened again.
“Madam.”
“Yes, please speak.”
“Do you truly believe that a single lump of iron can change the tide of battle?”
Cao Shen’s eyes began to shine sharply. It was somewhat abrupt, but I immediately understood. It was the fundamental question of what a mere auxiliary tool for riding horses could possibly do on a battlefield dominated by chariots.
‘Of course he would be skeptical.’
Fortunately, this was a topic I was confident in. History enthusiasts naturally double as military enthusiasts, after all. I set down my teacup and nodded firmly.
“Yes. I am certain.”
“And the reason?”
“Because both the horse freed from the constraints of the chariot and the person freed from the constraints of riding technique possess limitless potential.”
I summarized it simply for now. I was ready to explain, if necessary, just how efficient the flexibility and shock power of cavalry could be on the battlefield.
“……I see.”
But Cao Shen nodded more readily than expected. What? I thought he would argue.
After a brief pause, he continued speaking.
“Madam, your way of thinking is truly unlike that of an ordinary woman.”
“I hear that quite often.”
I was no longer the type to be flustered by such insight. I smiled brightly and shamelessly shrugged my shoulders.
“If I’m going to continue living as the wife of Liu Ji, I figured I needed at least this much personality.”
“……Ha, I can somewhat relate to that.”
Cao Shen showed a faint smile for the first time in a while. He quickly erased it, however, and looked at me with his usual stern expression.
“Then, I shall trust in your conviction this once. I hope it yields good results.”
Cao Shen drained the remaining tea in one gulp. His evaluation of the stirrup seemed to be half skepticism, half anticipation. I smiled gently and nodded.
“Of course, Lord Cao. You will not be disappointed.”