Chapter 11: Probability Theory
As soon as he started playing, Lin Qian unsurprisingly lost five or six rounds in a row, totaling two Pesos lost.
The Spanish sailors saw Lin Qian losing freely and all showed enthusiastic smiles.
Under the influence of alcohol and gambling, the sailors began to open up.
“Are you sailors on the Manila Galleon?” Lin Qian asked casually.
“Correct, Santa Ana… raise!”
“I’ve heard you sailed from across the ocean. Is there really land over there?” Lin Qian deliberately played dumb as he asked, while calling the bet.
“Across is America, the continent of the New World!”
“I don’t believe it. If there’s really a continent, why don’t you go there?” While Lin Qian spoke, he lost that hand, and eight Rials were divided among the Spaniards.
The cost of gathering information had accumulated to three Pesos.
“You need monsoon and Black Tide for departure, and have to wait some time.”
Lin Qian deduced that the so-called monsoon was the southwest monsoon, formed by the northward shift of the subtropical high-pressure belt after the start of summer each year.
Manila’s merchant ships also had to wait for the southwest monsoon to return to Great Ming.
The so-called Black Tide was ocean current. Combining his knowledge of geography from his previous life, the ocean currents of the entire North Pacific generally moved clockwise. To go to America, one had to successively ride the Japan warm current and North Pacific warm current.
When returning from America to Manila, ride the North Equatorial warm current again.
And now it was February.
Thus, the Manila Galleon still had at least two or three months before departure.
The Spanish sailors thought they hadn’t revealed anything, but actually they had spilled all the intelligence.
Afterwards, Lin Qian used the same method to buy all the information he wanted.
By dawn, he had spent more than twenty Pesos on intelligence fees.
The Spanish sailors’ intelligence had been squeezed dry, so Lin Qian prepared to get up and leave.
However, the Spanish sailors grew more spirited the longer they played; after all, the money they won that night equaled a month’s salary.
Lin Qian tried to leave several times but was stopped by the Spaniards each time.
A Spanish sailor took a cowhide bag from his waist, placed it on the table, and said, “If you win the next hand, this is yours. How about it?”
Lin Qian looked closely and saw the bag contained exactly the astrolabe he needed.
Seeing Lin Qian’s interest in navigation, that sailor decided to use the astrolabe as a bet to keep him there.
In his view, Lin Qian had lost all evening and could not possibly suddenly turn lucky and win the astrolabe.
Lin Qian’s sleepiness faded by more than half; he got excited and sat back at the card table.
The playing cards game they played was called “Ombre”; each got three cards to compare values. The betting method was similar to Texas Hold’em, with players taking turns to raise while others chose to call or fold.
If folding, bets already placed could not be taken back.
When all bets matched, cards were revealed, and the winner took all bets on the table.
The sailor dealt.
Lin Qian got two twelves and an eight, totaling thirty points—a very strong hand.
“One Peso.” A Spanish sailor placed a silver coin on the table.
“Call.” Lin Qian promptly took out a silver coin.
He knew that once he called, someone would definitely have a hand just beating his.
The rest called and revealed; sure enough, one had thirty-two points.
After playing all evening, Lin Qian had long spotted the Spaniards cheating.
That deck was well-worn, with stains on each card that seemed accidental but actually followed patterns.
The Spanish sailors read the points from the stains; Lin Qian called only to lure them into the trap.
Before the next round, Lin Qian used changing luck as an excuse and asked the bartender for a new deck.
By then, the Spanish sailors utterly underestimated him. Even without marks, they were confident of winning and let Lin Qian change the deck.
This round, Lin Qian’s three cards were nine, four, and ten, totaling twenty points.
These Spanish playing cards had four suits, each with twelve cards marked one to twelve points, totaling forty-eight cards.
By game rules, randomly drawing three cards to compare allowed direct calculation of win rate via probability.
But the computation was too complex.
Lin Qian had a simple method: the median and average point total of the forty-eight cards were both 6.5.
Twenty points averaged 6.67, higher than the overall median, so win rate clearly above 50%.
Simplifying 6.67 within the same suit gave a win rate of about 55.56%.
This algorithm was imprecise but sufficient for betting decisions.
“Raise.”
Lin Qian directly took out five Pesos.
Eight Spaniards sat at the table; if all called, Lin Qian could win thirty-five Pesos at once.
He could not only recoup the intelligence fees but also make a small profit.
However, five Pesos was a huge sum; most Spanish sailors folded.
Only one gritted his teeth and called.
After reveal, that one had nineteen points, just losing to Lin Qian.
Though no big fish was hooked, Lin Qian confirmed that after the deck change, the Spaniards could no longer cheat.
Now it was time for math showdown.
Lin Qian’s strategy: bet heavy whenever win rate exceeded 60%.
His funds far outstripped these Spanish sailors; he could afford multiple losses.
The more bets, the closer his win rate approached 60%.
……
Half an hour later, the Spanish sailors were cleaned out.
Each eyed red, plunged into self-doubt.
That astrolabe was now in Lin Qian’s hands to fiddle with.
Its principle and function resembled the sextant but used a pinhole to observe celestial bodies, lacking the sextant’s complex lenses.
The astrolabe indicated degrees with a cotton thread and lead weight hanging below.
This design limited it to stable voyages; rough seas made readings inaccurate—technically far inferior to the sextant.
Still, the scale on the astrolabe could somewhat address homemade sextant precision issues; the night was not wasted.
Lin Qian took the astrolabe and stood.
The Spanish sailors wanted to chase but saw a stack of silver coins left on the table.
Fifteen Pesos—not only covering their losses but with five extra.
Greed for small gains leads to big losses, an eternal truth.
Lin Qian’s plentiful gains that night meant he wouldn’t stint on silver.
Out the bar door, Lin Qian felt weary.
Back to the ship, he lay on the stern cabin bed without undressing and fell asleep.
When he woke, it was evening.
Lin Qian rose from bed, feeling refreshed.
Lin Qian summoned Mute Huang, showed the sextant design, explained its construction in detail, and gave him the single-tube telescope and astrolabe to make a prototype first.
Mute Huang took them, patted his chest, and left.
Lin Qian then had someone call Bai Langzai.
Bai Langzai entered the cabin to see Lin Qian doing push-ups, yesterday’s sundries on the table.
“You’re Tanka People, so good swimmer? How far underwater in one breath?” Lin Qian asked while pushing.
“Over one hundred seventy steps.”
“Really?” Lin Qian paused.
Ordinary people swimming fifty meters in one breath was impressive.
Over one hundred seventy steps neared three hundred meters—a terrifying distance.
Bai Langzai nodded sadly: “My sister could swim farther.”
Lin Qian stood, took a package from the table, and handed it to Bai Langzai: “One hundred seventy steps suffices.”
Bai Langzai opened it: copper wire, kelp, salt, and vinegar Lin Qian bought yesterday.
Wrapping copper wire with cast iron anchor chain, plus seawater as electrolyte, caused galvanic corrosion.
Salt and vinegar derusted the anchor chain surface, exposing fresh cast iron to speed reaction.
Kelp wrapped outside hid the copper wire.
Securing the galleon’s departure time and corroding its anchor chain—that was Lin Qian’s plan first step.
“Help me deliver these ‘local specialties’ there.”
Lin Qian pointed at the Manila Galleon outside the window.
