The flight from Boca Chica to Las Vegas takes about two and a half hours.
Elon Musk sent a small Cessna Citation jet. When it took off from Brownsville, the dusk at the southern end of Texas was dyeing Gulf of Mexico a rusty red.
Su Wantang was sitting by the window, looking at the gradually darkening wilderness under the wing of the plane and the scattered lights on the distant coastline.
Shen Zhiyi was sitting next to Zhao Chen, with a legal document spread out on the small table in front of her that she had not had time to review during the day.
But she closed it after turning two pages, leaning back in the chair and closing her eyes.
Zhao Chen took Zisha Pot out of the soft cloth bag and went to the tea table at the rear of the cabin to boil hot water.
When the aroma of tea slowly spread in the small cabin, Su Wantang turned around and looked at him.
She knows this action - every time Boca Chica leaves, Zhao Chen will make a pot of tea on the plane.
It was like trying to wash away the smell of burning welding guns and the chemical smell of coolant in the Elon Musk factory.
But today he made tea more slowly than usual. When filling the spout with water, he paused at the edge of the cup for a moment, as if he was thinking about something.
She didn't ask.
After following him for so long, she knew that he would naturally speak when he wanted to say something.
It was 7pm local time when the plane landed at Las Vegas.
The runway lights of Harry Reid International Airport flashed past the window,
The skyline of the casino spreads out in the distance, like a straightened neon strip.
The hotel Zhao Chen booked is at the southern end of Las Vegas Boulevard, not in the central casino area, but only a few minutes drive from the entertainment complexes of MGM and New York-New York.
"Where are we going tomorrow?"
Su Wantang asked as he lifted the suitcase off the conveyor belt.
"Let's talk tomorrow. Let's have dinner tonight and then take you somewhere."
Zhao Chen took the box in her hand and put Zisha Pot's soft cloth bag on her shoulder.
Shen Zhiyi dragged his luggage and walked beside him. "Where?"
"Casino."
Su Wantang and Shen Zhiyi turned their heads to look at him at the same time.
Zhao Chen's expression was very flat, with no tendency to be seen, but Shen Zhiyi recognized the very faint arc at the corner of his mouth - he was showing off.
Dinner was served at a Japanese restaurant on the second floor of the hotel.
Zhao Chen ordered sashimi and sushi, Su Wantang ordered udon, and Shen Zhiyi chose eel rice.
It was almost nine o'clock when the three of them finished eating. Zhao Chen paid the bill and led them through a corridor at the back door of the hotel and walked into the MGM casino lobby.
The air in the casino hall was hotter than outside, mixed with the smell of cigar smoke, cheap perfume and electronic music wafting from an unknown slot machine.
Above the head are rows of crystal chandeliers and ventilation ducts, and under the feet are walkways covered with dark patterned carpets.
The lights in the slot machine area flashed like an overturned neon box. There were people sitting in front of every machine, and the patterns on the screen rotated rapidly.
Further inside, there is the blackjack and roulette table area. The green baize table glows dimly under the overhead light, and the dealer's white shirt is particularly conspicuous under the light.
Zhao Chen Bypass the tables crowded with tourists whose minimum bet is only five US Dollar and head toward the high-limit area.
There is a bronze plaque hanging on the porch at the end of the corridor that reads "High Limit Salon".
After pushing the door open and entering, the voice suddenly became dull--
The electronic sound of the slot machine was isolated from the outside, leaving only the crisp sound of chips colliding and the low voice of the dealer reporting the numbers.
The table surface changed from green to dark blue, and the chip denomination changed from five US Dollar to the minimum one hundred US Dollar.
There are a lot fewer people and the atmosphere is much calmer.
Zhao Chen walked to a blackjack table.
There were only two people sitting on the table. One was a middle-aged man wearing a dark gray suit. The chips were piled high and he was staring at the cards with an expressionless face.
The other was a young man in a sweatshirt. He had very few chips in his hand and hesitated for a long time every time he placed a bet.
Zhao Chen didn't sit down, just stood behind the table and watched.
Su Wantang and Shen Zhiyi stood on both sides of him, the three figures standing like three quiet pillars behind the anxious gamblers.
At the end of the round, the dealer took away the chips on the table, and Zhao Chen took them to an empty table next to them that had not started yet.
He pulled up his chair, sat down, took out a few bills from his pocket and exchanged them for chips.
The dealer came over, Zhao Chen placed the minimum bet, and the dealer began to shuffle and deal the cards.
"Did you know blackjack is the only game in the casino that can be beaten by math?"
Zhao Chen turned over his hole cards, a ten and a six. He put the cards on the table and signaled to continue asking for cards.
"Because of card counting?" Shen Zhiyi sat down next to him and watched the dealer push over another card.
"Because card counting. But card counting is not the kind of card counting in movies.
It is a mathematical method based on probability. In 1962,
A mathematician named Edward Thorp published a paper on "Proceedings of the National Academy of Sciences" titled "The Optimum Strategy in Blackjack".
He used probability theory to prove that if players can keep track of the cards that have been played,
By adjusting your bet based on the remaining cards, you can achieve positive expected value at the blackjack table in the long run."
He turned over the third card that the dealer had just dealt, a four.
Twenty o'clock.
He stopped and the dealer turned over his cards, seventeen.
Zhao Chen won.
He pushed aside his winning chips and did not continue to bet.
"The core of Thorp's theory is that blackjack is not a game of pure luck.
Each card changes the composition of the remaining deck.
As the proportion of high cards - tens, jacks, queens, kings, aces - in the remaining pile increases, the player's advantage increases.
Because the dealer must ask for cards below seventeen points, the more high cards there are, the greater the probability of the dealer busting the card.
Thorp invented a system to assign a value to every card that appears--
Low cards will count as positive points, and high cards will count as negative points. When the points accumulate to a certain threshold, the player will place a large bet.
When the score is zero or negative, the player places a minimum bet.
In the long run, this system can allow players to obtain a positive expected value of about 1.5% to 2%."
Su Wantang sat down next to him, took a chip and rolled it between his fingers.
"One to two percent doesn't sound like much."
"Not much for a single bet.
But if the time is extended and the number of bets is enlarged, the positive expected value of one to two percent will become a considerable number under the compound interest effect.
This is why after Thorp's paper was published, Las Vegas's casino began to panic.
They sent people to follow him and try to figure out how he won the money.
But everything Thorp does is legal--
He didn't cheat, he didn't steal cards, he just used mathematical calculations to change his betting strategy.
The casino had no choice but to blacklist him."
Zhao Chen took back the chips and signaled the dealer to continue dealing cards.
He looked at the hole cards of the new round, then looked at the bright cards on the table, and did a quick calculation in his mind -
"Loss fifteen. No bets in this round."
"Thorp later wrote his experience at the gambling table into a book called "Beat the Dealer".
After this book was published in 1962, it became the bible for blackjack players.
But what really makes Thorp make money is not the casino, but Wall Street.
The betting method based on probability and Kelly Criterion that he summarized from the gambling table was later brought to the financial market.
He opened his own Hedge Fund, called Princeton/Newport Partnership.
From 1969 to 1988, the fund's annual return was approximately 19 percent, with no loss in a single year.
Use table math to manage a Hedge Fund -- that's what Thorp does."