Nine lines of fate : a gambler

It's all over... Kevin watched the dealer take away his last chip. At this moment, what he felt was not despair and powerlessness, but a kind of relief. Three weeks of high-intensity gambling had made his originally black and shiny hair withered. He had not taken a shower for a long time, making his hair very greasy and clinging to his head, and his eyes were blank. He originally had a tall and well-proportioned figure, with a height of 1.85 meters, and his relatively solid muscles could be seen from the outline of his black shirt. However, the long-term reversal of day and night at this moment made him exhausted. He hunched his back and almost slumped in the chair. In all the casinos in Macau, there are always many gamblers who have lost everything wandering around. When they see lucky gamblers winning a lot of money, they will shout 'awesome, spirited boss, red in a row, red clearance' and so on, asking for some 'red money'. If these unfortunate people are lucky enough, they may get thousands of Hong Kong dollars from the winners. If they are unlucky, their family members will be scolded. For them, being scolded is nothing compared with the money and the fake hope of coming back. It is precisely the long-term wandering in the casino that enables these bankrupt gamblers to develop extraordinary discerning eyes and can quickly distinguish who wins money and who loses money. These gamblers who want red money have known Kevin for a long time. He spends money generously and doesn't like to talk. The best thing is that he has really made a lot of money in the past few weeks, and every time he wins money, he silently rewards them. Give it to the person next to you. As the saying goes, when a tree falls, the hozen disperses. When these people saw the dark gray face of Mr. Kevin, they quietly dispersed and went to find their next boss. Kevin lost 5 million HK$, including all his and his parents’ savings, and even borrowed 1 million HK$ from various lending software in mainland China (the annual interest rate is nearly 20%, which means that these lending institutions believe that there is close to 1/5 probability that Kevin will default). These so-called savings were mainly given by my parents to pay the down payment for buying a house in Beijing. It can be said that they are money saved by my parents’ hard work throughout their lives, and only with that house can he find a wife that he would be satisfied with. On February 24th, 20:30, Kevin finally stood up reluctantly, his head was still blank, and he slowly walked out of the casino. As always, there are some coquettish women outside the casino. Some of them are freelancers, and some of them are gamblers themselves, trying to make some money to make up for their losses. These prostitutes wear very heavy makeup to cover their dry skin. They are also older, some are even over 35 years old, more than 5 years older than Kevin. Of course, Kevin has no intention of them now. He got into a taxi and headed back to the Londoner Macau. Along the way, he cannot stop thinking: how did he lose? He began to recall the past few weeks from the beginning. He only plays European roulette. The ball will roll to a number in each game. Among the 37 numbers, 1-18 are low numbers, 19-36 are high numbers, and 0 is also included. The casino's advantage is about 2.7%. He believes that if the casino does not cheat, the roulette numbers will show mean reversion. I.E. in a day's gambling, if there are more 'high' numbers on a table, then the probability of 1-18 ('low') appearing next will be higher. According to this logic, he arrives at the Grand Lisboa Casino on time at 14:00 every afternoon, chooses a gambling table with more 'high' or 'low' numbers gambling tables, betting on 'low' or 'high' constantly. According to the theory of mean reversion, there is a high probability that he can make a profit when he leaves at 0:30 the after day. Here’s how he bets: The maximum bet amount for non-VIP gaming tables is HK$500,000, and the minimum bet is HK$500. He decided to always bet on low(1-18)/high(19-36) at gambling tables with a high frequency of high/low. The starting bet was HK$ 6,000. If he won, he would double his bet, and if he lost, he would halve his bet. Therefore, his betting upper limit is HK$48,000 and the lower limit is HK$750. Each rotation of the roulette lasts approximately 90 seconds. After winning or losing 4 times in a row, the betting starting point will be HKD 6,000 again. Since there are 18 numbers that are high and 18 numbers that are low, a total of 37 numbers, then the probability of winning in one bet is 48.65%. If we define winning 4 times in a row or losing 4 times in a row as one round, the probability of winning in one round is 5.60%, corresponding to a profit of HK$48,000, and the probability of failure in one round is 6.95%, corresponding to a loss of HK$11,250. Profit expectation after losing and winning in one round = 5.60%*48,000-6.95%*11,250=HK$1,906.13. As long as sufficient time, stable arbitrage can be achieved. In addition, due to mean reversion, the actual winning rate will be higher if a gambling table with more high/low numbers is chosen. He followed this betting principle from February 10th until February 16th. Although the daily profits fluctuated greatly, on average, he made almost more than 25,000 Hong Kong dollars every day, and won nearly 200,000 Hong Kong dollars in total. Within a week, many bankrupt gamblers knew about Mr. Kevin in the roulette area, and they were waiting to ask for some red money when Mr. Kevin came. There were always a lot of people around Kevin. On February 17, Mr. Wang in the VIP room saw Kevin. He found Kevin, and all this was the beginning of the nightmare...