As the pack thundered around the final bend, two horses muscled ahead. “It’s Mascot Treasure a length in front, but Bobo Duck is gunning him down,” said the commentator, voice rising. “Bobo Duck in front. Mascot fighting back.” The crowd roared as the riders raced across the finish line. Bobo Duck edged Mascot Treasure, and Frat Rat came in third.

Across the road from Happy Valley, 27 floors up, two Americans sat in a plush office, ignoring a live feed of the action that played mutely on a television screen. The only sound was the hum of a dozen computers. Bill Benter and an associate named Paul Coladonato had their eyes fixed on a bank of three monitors, which displayed a matrix of bets their algorithm had made on the race, some 51,381 in all.

Benter and Coladonato watched as a software script filtered out the losing bets, one at a time, until there were 36 lines left on the screens. Thirty-five of their bets had correctly called the finishers in two of the races, qualifying for a consolation prize. One wager had correctly predicted all nine horses.

“F***,” Benter said. “We hit it.”

It wasn’t immediately clear how much they had made, so the two Americans attempted some back-of-the-envelope maths until the official dividend flashed on TV eight minutes later. Benter and Coladonato had won a jackpot of US$16 million. Benter counted the zeros to make sure, then turned to his colleague.

“We can’t collect this – can we?” he asked. “It would be unsporting. We’d feel bad about ourselves.” Coladonato agreed they could not. On a nearby table, pink betting slips were arranged in a tidy pile. The two men picked through them, isolating three slips that contained all 36 winning lines. They stared at the pieces of paper for a long time.

Then they posed, laughing, for a photo – two professional gamblers with the biggest prize of their careers, one they would never claim – and locked the tickets in a safe. No big deal, Benter figured. They could make it back, and more, over the rest of the racing season.

Veteran gamblers know you cannot beat the horses. There are too many variables and too many possible outcomes. A front-runner breaks a leg. Jockeys fall. Champion thorough­breds decide, for no apparent reason, that they are simply not in the mood. American sportswriter Roger Kahn once called the sport “animated roulette”. Play for long enough and failure is not just likely but inevitable, so the wisdom goes.

“If you bet on horses, you will lose,” says Warwick Bartlett, who runs specialist gambling consultancy Global Betting & Gaming Consultants and has spent years studying the industry.

But what if that were not true? What if there was one person who had masterminded a system that guaranteed a profit? One person who had made almost a billion dollars, and who had never told his story – until now?

In September, after a long campaign to reach him through friends and colleagues, I received an email from Benter. “I have been avoiding you, as you might have surmised,” he wrote. “The reason is mainly that I am uncom­fort­able in the spotlight by nature.” He added, “None of us want to encourage more people to get into the game.”

But in October, Benter agreed to a series of interviews in his office in downtown Pittsburgh, in the United States.

The tasteful space is furnished with metre-tall Chinese vases and a marble fireplace, with sweeping views of the Monongahela River and freight trains rumbling past.

Benter, 61, walks with a slight stoop. He looks like a university professor, his wavy hair and beard streaked with grey, and speaks in a soft, slightly Kermit-y voice. He tells me he had been driven only partly by money – and I believe him. With his intelli­gence, he could have become richer faster working in finance.

Benter wanted to conquer horse betting not because it was hard, but because it was said to be impossible. When he cracked it, he actively avoided acclaim, outside the secretive band of geeks and outcasts who occupy his chosen field. Some of what follows relies on his recollections, but in every case where it has been possible to corroborate events and figures, they have checked out in interviews with dozens of individuals, as well as in books, court records and other documents.

Triple Trio jackpot revives memories of glory days for the legendary bet

Only one thing Benter tells me will turn out to be untrue. It is at the outset of our conversations, when he says he does not think I will find anything interesting to write about in his career.

Benter grew up in a Pittsburgh idyll called Pleasant Hills. He was a diligent student and a keen Scout, and he began to study physics in college. His parents had always given him freedom (he had hitchhiked across Europe to Egypt, and driven through Russia) and in 1979, at the age of 22, he put their faith to the test. Benter left school, boarded a Greyhound bus, and went to play cards in Las Vegas.

The youngster had been enraptured by Beat the Dealer, a 1962 book by American maths professor Edward Thorp that describes how to overcome the house’s advantage in black­jack. Thorp is credited with inventing the system known as card counting: keeping track of the number of high cards dealt, then betting big when it is likely that high cards are about to fall. It takes concentration, and lots of hands, to turn a tiny advantage into a profit, but it works.

Thorp’s book was a beacon for shy young men with a gift for mathematics and a yearning for a more interesting life. When Benter got to Las Vegas, he worked at a 7-Eleven for US$3 an hour and took his wages to budget casinos. The Western – with its dollar cocktails and shabby patrons getting drunk at 10am – and the faded El Cortez were his turf.

He did not mind the lack of glamour. It thrilled him to see scientific principles play out in real life. On a good day, Benter might win about US$40, but he had found his métier – and made some friends. Fellow Thorp acolytes were easy to spot on casino floors, tending to be conspicuously focused and sober. Like them, Benter was a complete nerd. He had a small beard, wore tweedy jackets and talked a lot about probability theory.

In 1980, he had just applied for a job as a night cleaner at McDonald’s when his buddies introduced him to the man who would change his life. Alan Woods was the leader of an Australian card-counting team that had recently arrived in Las Vegas. Woods was then in his mid-30s, with a swoop of grey hair and cold blue eyes. Once an insurance actuary with a wife and two children, he had decided one day that family life was not for him and began travelling the world as an itinerant gambler.

Woods impressed Benter with his tales of fearlessness, recounting how he had sneaked past airport security in Manila, in the Philippines, with US$10,000 stuffed into his underwear. Most appealing, he pursued the card counter’s craft with discipline. His team pooled its cash and divided winnings equitably. Having more players reduced the risk of a run of bad luck wiping out one’s bankroll, and the camaraderie offset the solitary nature of the work. Benter joined the group.

Within six weeks, Benter found himself playing blackjack in Monte Carlo, served by waiters in dinner jackets. He felt like James Bond, and his earnings grew to about US$80,000 a year. Benter abandoned any idea of returning to college. When his mother’s friends in Pittsburgh asked how his studies were going, she told them, “Bill’s travelling right now.”

Benter and his teammates got a house in the Vegas suburbs, living like geeky college fraternity brothers. Woods strictly forbade drinking on the job, so the men would wait until after their shifts to knock back beers and trade stories of scrapes with casino security, who were constantly on the lookout for card counting. Bull-necked pit bosses patrolled the floors. A suspicious player would be told to leave or, worse, “backroomed”: interrogated in a dingy office. There were rumours of counters being beaten and drugged. Benter thought the treatment was unjustified. He was not a cheat. He just played smart.

After a couple of years, Benter was playing quietly at the Maxim one day when a meaty hand descended on his shoulder. “Come with me,” said a burly guy in a suit. In the back, Benter was shoved into a chair and told to produce some identification. He refused. The guard walked out, and an even more menacing guy walked in: “Show me your f***ing ID!” Benter got out his wallet.

Afterwards (it was probably 1984), Benter, Woods and some of their partners earned a place in the Griffin Book, a blacklist that detective agency Griffin Investigations circu­lated to casinos. On top of the indignity of having their mug shots next to hustlers and pickpockets, the notoriety made it almost impossible for them to keep playing in Vegas. They needed to find another game.

Woods knew there were giant horse-betting pools to tap in Asia, and that the biggest of all was run by the Hong Kong Jockey Club. Established in the British colony in 1884 as a refuge for those who wanted a stretch of England’s green and pleasant land in their subtropical colony, the club changed over time into a gambling monopoly overseen by the govern­ment. By the 1980s, meetings at its two race­courses, at Happy Valley and Sha Tin, were packed during a racing season that extended from September to July. Hong Kong’s population was then about 5.5 million, but it bet more on horses than the entire US, reaching about US$10 billion annually by the 90s.

Hong Kong racing uses a pari-mutuel (also known as “total­iser”) system. Unlike odds in a Vegas sportsbook, which are set in advance and give a decisive edge to the house, pari-mutuel odds are updated fluidly, in proportion to bets being made. Winners split the pool, and the house skims a commission of about 17 per cent. (After costs, the Jockey Club’s take goes to charity and the government, providing as much as 10 per cent of Hong Kong’s tax revenue.)

To make money, Benter would have to do more than pick winners: he needed to make bets with a profit margin greater than the club’s 17 per cent cut.

Counting the costs of misery caused by Macau’s casinos

He went to the Gambler’s Book Club, a Vegas institution, and bought everything he could find on horses. There were lots of “systems” promising incredible results, but to him they seemed flimsy, written by journalists and amateur handi­cappers. Few contained real maths.

Benter wanted something more rigorous, so he went to the library at the University of Nevada at Las Vegas, which kept a special collection on gaming. Buried in stacks of periodicals and manuscripts, he found what he was looking for – an academic paper titled “Searching for Positive Returns at the Track: A Multinomial Logit Model for Handicapping Horse Races”.

Benter sat down to read it and, when he was done, he read it again. The paper argued that a horse’s success or failure was the result of factors that could be quantified probabilistically. Take variables (straight-line speed, size, winning record, the skill of the jockey, etc), weight them, and presto! Out comes a prediction of the horse’s chances. More variables, better variables and finer weightings improve the predictions. The authors were not sure it was possible to make money using the strategy and, being mostly interested in statistical models, did not try hard to find out. “There appears to be room for some optimism,” they concluded.

Benter taught himself advanced statistics and learned to write software on an early PC with a green-and-black screen. Meanwhile, in the autumn of 1984, Woods flew to Hong Kong and sent back a stack of yearbooks containing the results of thousands of races. Benter hired two women to key the results into a database by hand so he could spend more time study­ing regressions and developing code. It took nine months. In September 1985, he flew to Hong Kong with three bulky IBM computers in his checked luggage.

The Hong Kong that greeted Benter was a booming financial centre. The crowded skyline that had recently inspired Ridley Scott’s dystopian megacity in the movie Blade Runner (1982) seemed to sprout high-rise towers weekly.

Benter and Woods rented a microscopic flat in a dilapidated building. Warbling Cantonese music drifted through stained walls and neighbours spent nights shouting in the hall. Their office was an old desk and a wooden table piled high with racing newspapers. If they went out at all, it was to the McDonald’s down the street.

Twice a week, on race days, Benter would sit at the computer and Woods would study the racing form. Early on, the betting program that Benter had written spat out bizarre predictions, and Woods, with his year-long head start studying the Hong Kong tracks, would correct them. They used a telephone account at the Jockey Club to call in their bets and watched the races on TV. When they won, there were satisfied smiles only. They were professionals; cheering and hooting were not in the script.

A Hong Kong racing Hall of Fame needs to be established

Between races, Benter struggled to make his algorithms stay ahead of a statistical phenomenon called gambler’s ruin. It holds that if a player with limited funds keeps betting against an opponent with unlimited funds (that is, a casino, or the betting population of Hong Kong), he will eventually go broke, even if the game is fair. All lucky streaks come to an end, and losing runs are fatal.

One approach, familiar to Benter from his blackjack days, was to adapt the work of a gunslinging Texas physicist named John Kelly Jnr, who had studied the problem in the 50s. Kelly imagined a scenario in which a horse racing gambler has an edge: a “private wire” of fairly reliable tips. How should he bet? Wager too little, and the advantage is squandered. Too much, and ruin beckons. (Remember, the tips are good but not perfect.) Kelly’s solution was to wager an amount in line with the gambler’s confidence in the tip.

Benter was struck by the similarities between Kelly’s hypo­thetical tip wire and his own prediction-generating software. They amounted to the same thing: a private system of odds that was slightly more accurate than the public odds. To simplify, imagine that the gambling public can bet on a given horse at a payout of four to one. Benter’s model might show that the horse is more likely to win than those odds suggest – say, a chance of one in three. That means Benter can put less at risk and get the same return; a seemingly small edge can turn into a big profit. And the impact of bad luck can be diminished by betting thousands and thousands of times. Kelly’s equations, applied to the scale of betting made possible by computer modelling, seemed to guarantee success.

Super-punter Woods quietly masterminded a revolution

If, that is, the model were accurate. By the end of Benter’s first season in Hong Kong, in the summer of 1986, he and Woods had lost US$120,000 of their US$150,000 stake. Benter flew back to Vegas to beg for investment, unsuccess­fully, and Woods went to South Korea to gamble. They met back in Hong Kong in September. Woods had more money than Benter and was willing to recapitalise their partnership – if it was renegotiated.

“I want a larger share,” Woods said.

“How much larger?” Benter asked.

“Ninety per cent,” Woods said.

“That is unacceptable,” Benter said.

Woods was used to being the senior partner in gambling teams and getting his way. He never lost his temper, but his mind, once set, was like granite. Benter was also unwilling to budge. Their alliance was over. In a fit of pique, Benter wrote a line of code into the software that would stop it from functioning after a given date – a digital time bomb – even though he knew it would be easy for Woods to find and fix it later. Woods would keep betting algorithmically on horses, Benter was sure of that. He resolved that he would, too.

Benter’s Las Vegas friends would not stake him at horse racing, but they would at blackjack. He took their money to Atlantic City and spent two years managing a team of card counters, brooding and working on the horse racing model in his spare time. In September 1988, having amassed a few hundred thousand dollars, he returned to Hong Kong. Sure enough, Woods was still in the city. The Australian had hired programmers and mathematicians to develop Benter’s code and was making money. He had moved into a penthouse flat with a spectacular view. Benter refused to speak to him.

Benter’s model required his undivided attention. It moni­tored about 20 inputs – just a fraction of the countless factors that influence a horse’s performance, from wind speed to what it ate for breakfast. In pursuit of mathematical perfec­tion, he became convinced that horses raced differently according to temperature, and when he learned that British meteorologists kept an archive of Hong Kong weather data in southwest England, he travelled there by plane and rail. A bemused archivist led him to a dusty library basement, where Benter copied years of figures into his notebook. When he got back to Hong Kong, he entered the data into his computers – and found it had no effect whatsoever on race outcomes. Such was the scientific process.

Other additions, such as the number of rest days since a horse’s last race, were more successful, and in his first year after returning to Hong Kong, Benter won (as he recalls) US$600,000. The next racing season, ending in the summer of 1990, he lost a little but was still up overall. He hired an employee, Coladonato, who would stay with him for years, and a rotating cast of consultants: independent gamblers, journalists, analysts, coders and mathematicians. When the volume of bets rose, he recruited English-speaking Filipinos from the ranks of the city’s domestic helpers to relay his bets to the Jockey Club’s Telebet phone lines, reading wagers at the rate of eight a minute.

A breakthrough came when Benter hit on the idea of incorporating a data set hiding in plain sight: the Jockey Club’s publicly available betting odds. Building his own set of odds from scratch had been profitable, but he found that using the public odds as a starting point and refining them with his proprietary algorithm was dramatically more profitable. He considered the move his single most important innovation, and in the 1990-91 season, he says, he won about US$3 million.

‘Tsunami of illegal betting has arrived’: Hong Kong Jockey Club warns it could kill horse racing

The following year, the Hong Kong Jockey Club phoned Benter at an office he had established in Happy Valley. He winced, remembering the meaty hand of the Las Vegas pit boss on his shoulder. But instead of threatening him, a Jockey Club salesperson said, “You are one of our best customers. What can we do to help you?” The club was not a casino trying to root out gamblers who regularly beat the house; its aim was to maximise betting activity so more revenue would be available for Hong Kong charities and the government.

Benter asked if it was possible to place his bets electro­nically instead of over the phone. The Jockey Club agreed to install what he called the “Big CIT”, a customer input terminal. He ran a cable from his computers directly into the machine and increased his betting.

Benter had achieved something without known prece­dent: a kind of horse racing hedge fund, and a quantitative one at that, using probabilistic modelling to beat the market and deliver returns to investors. Probably the only other of its kind was Woods’ operation, and Benter had written its code base. Their returns kept growing. Woods made US$10 million in the 1994-95 season and bought a Rolls-Royce that he never drove. Benter bought a stake in a French vineyard. It was impos­sible to keep their success secret, and they both attracted employees and hangers-on, some of whom switched back and forth between the teams of Benter and Woods.

One was Bob Moore, a manic New Zealander whose passions were cocaine and video analysis. He would watch footage of races to identify horses that should have won but were bumped, blocked and prevented from doing so. It worked as a bad-luck adjuster and made the algorithms more effective.

The computer-model crowd spent nights in Wan Chai – a honeypot of gaudy bars and pole dancers. Moore favoured Ridgway’s pool bar, where he would start fights and boast about his gambling exploits. Woods did not drink much, but he enjoyed the drug Ecstasy, and he could be found most nights in Neptune II, a neon-dungeon nightclub full of drunk businessmen and much younger women.

Benter was a more reserved presence. He could often be seen sitting at the end of a bar, engaged in quiet conversation. Over time an aura built up around him. To the small group of insiders who knew that software had conquered Happy Valley – perhaps a dozen people – Benter was the acknowledged master. Even Woods (in an interview he gave to an Australian journalist) admitted that his rival’s model was the best. But the two men could not resolve their differences. When Benter saw his old partner in Wan Chai, he would smile politely and walk away. They had gone 10 years without speaking.

Throughout 1997, a shadow loomed over Hong Kong. After 156 years of colonial rule, the British were set to hand the territory back to China on July 1. There were news reports of Chinese troops massed at the border, and many feared it would be the end of Hong Kong’s freewheeling capitalism. Beijing tried to reassure residents that their most treasured customs would be protected. “Horse racing will continue, and the dancing parties will go on,” said Deng Xiaoping, China’s paramount leader.

Benter faced an additional and more peculiar anxiety. A month before the handover, his team won a huge Triple Trio jackpot. They were in the middle of an epic winning season, up more than US$50 million. The Jockey Club normally put Triple Trio winners in front of the TV cameras to show how, for example, a nightwatchman had changed his life with a single bet. This time, nobody wanted to tout the fact that the winner was an American algorithm.

The club had come to see the syndicates’ success as a headache. There was no law against what they were doing, but in a pari-mutuel gambling system, every dollar they won was a dollar lost by someone else. If the everyday punters at Happy Valley and Sha Tin ever found out that foreign computer nerds were siphoning millions from the pools, they might stop playing entirely.

Benter had his Big CIT privileges revoked. On June 14, one of his phone operators called the Telebet line and was told, “Your account has been suspended.” Woods was also blocked. Club officials issued a statement saying they had acted to “protect the interests of the general betting public”.

Benter flew back to Vegas, as he did every summer, to think about his next move. He reread the club’s statement. Phone betting was out, but nowhere did it say he was prohi­bited from betting altogether. He had an idea. As in his black­jack days, it would require a low profile.

One Friday evening that autumn, after the handover of the territory to China, Benter paid for a hotel room in Hong Kong’s North Point district. He made sure it was a space on the ground floor for easy access. He had helpers haul in laptops, a 20kg printer and stacks of blank betting slips. On Saturday morning – race day – they checked the internet connection and put a do-not-disturb sign on the door.

Crackdown in Hong Kong on illegal betting and fake soccer goods ahead of World Cup

At 1.45pm, 15 minutes before the first race, the laptops received lines of bets from Benter’s Happy Valley office. The printer began to suck in blank tickets and churn them out with black marks in the relevant betting boxes.

Eight minutes to the off, Benter grabbed a pile of 80-odd printed tickets and a club-issued credit voucher worth HK$1 million and bolted for the door. Across from the hotel was an off-track betting shop. It was loud and smoky inside, and he found an automated betting terminal free at one side of the room. Two minutes to go. He started feeding in tickets, one after another after another, until the screen flashed a message: “Betting closed.”

Benter hurried back to the hotel room to see which wagers had hit. At 2.15pm, the laptops downloaded the next set of bets from the office. Time to go again. Simultaneously, people hired by Benter were doing the same in different parts of Hong Kong.

Benter’s solution to the phone ban was time-consuming and required him to manage teams of runners, who risked being robbed. But it was almost as profitable as his old arrange­ment. The club continued to exchange his cash vouchers for cheques, and no one came to shut him down. Woods continued betting in a slightly different way, sending members of an extended roster of Filipina girlfriends directly to the racetrack with bags full of cash.

Suicidal gambler rejected friends’ pleas to seek help

Publicity is a hex for professional gamblers. That autumn, an increasingly erratic Moore drew more attention to algo­rithmic betting, first by bragging to the local press – who nicknamed him the “God of Horses” – and then by fatally overdosing on sleeping pills.

Hong Kong’s tax authority began to investigate the Woods syndicate. By law, gambling winnings were exempt from taxation, but company profits were not. The question was whether the syndicates had moved beyond conventional betting and started behaving like corporations. The implica­tions would be dire if the Inland Revenue Department decided to tax profits retroactively. When agents asked Woods for a list of his investors, he fled to the Philippines.

Benter continued to operate his betting scheme through to the turn of the millennium, with his model expanding to track more than 120 factors per horse, but the logistics were proving a grind. He felt disconnected from his gambler friends in Wan Chai – a nocturnal clique of geeks and rogues. He had started mixing with a more professional crowd, adopting their dress code of smart suits and ties, and he had taken a more active role in the local Rotary Club chapter. Benter embraced its motto of “service above self”, giving away millions of dollars anonymously and visiting impoverished schools in China and refugee camps in Pakistan.

For the first time, he thought seriously about quitting and moving back to the US. If it all has to end, he thought, I’ve had an incredible run.

It was then, in November 2001, that he decided to have a final punt on the Triple Trio. Benter had avoided major prizes since 1997 for fear of angering the Jockey Club’s management, but this jackpot was too big to resist. Wagering on it was something of a lark, albeit an expensive one: he spent HK$1.6 million on the 51,000 combinations. If he won, he decided, he would leave the tickets unclaimed. Club policy in such cases directed the money to a charitable trust.

After Bobo Duck, Mascot Treasure and Frat Rat romped across the finish line – and then days turned into weeks, with no one collecting the prize – Benter was unprepared for the level of mounting public interest. “The ghost of the unclaimed $118 million Triple Trio,” wrote the racing columnist for the South China Morning Post, “is still banging around like an unwanted poltergeist.”

Outlandish theories spread across Hong Kong. One held that the winner had watched the last leg and died of shock.

Finally, Benter sent an anonymous letter to the Jockey Club’s directors explaining his intentions. But the organisation never shared it with the public. At the time, the club’s head of betting, Henry Chan Shing-kai, told the South China Morning Post that there was no way of knowing who the ticket holder was. “Although this is bad luck for one winner,” he said, “it means there will be a lot of winners through the charities.”

Later in 2001, without any warning, Jockey Club officials lifted the telephone betting ban. It was as if Benter’s gift had appeased the gambling gods. The club also bowed to public pressure and allowed customers to wager over the internet from their homes. Benter opted to move back to Pittsburgh, where he continued to bet. He did not want to spend his life in Hong Kong.

How Hong Kong Jockey Club caught Nash Rawiller in ‘tips for gifts’ web

In Manila, Woods lived like a hermit, bingeing on drugs for days at a time, waited on by young women he hired to keep him company. He employed gamblers remotely in Australia and Hong Kong, but he was a difficult boss; he accused staff of stealing, and once he made everyone take IQ tests before telling them all how much smarter he was. Woods started calling himself “Momu” – short for “master of my universe”.

In December 2007, he sent a letter to Business Review Weekly, an Australian magazine, asking to be considered for its rich list. “I had planned to delay my hope for inclusion until I could make it into the top 10,” he wrote. “However, as of today, it does not appear I will live long enough.”

Woods had been diagnosed with cancer. He came back to Happy Valley for treatment; the Hong Kong Sanatorium & Hospital was within sight of the racetrack. He spent his final days beating his friends at the Chinese card game chor dai di, and died on January 26, 2008, at the age of 62.

Interviews with Woods’ friends, employees and other sources indicate he had amassed a fortune of A$900 million (then about US$800 million). Mike Smith, a former Hong Kong policeman who knew Woods, wrote about him in his book In the Shadow of the Noonday Gun (2012): “He left a very simple will that pretty much summed up his lifestyle. Assets: A$939,172,372.51. Liabilities: A$15.93.”

Woods left the bulk of his estate to his two children in Australia and gave token sums to various ex-girlfriends, including a Filipina who said he had fathered her child. A wake was held in a bar at the Happy Valley racetrack and attended by an eclectic crowd of gamblers and hustlers. To the last, Woods never believed that Benter had won the 2001 Triple Trio and given up the jackpot.

“Gambling,” Benter tells me in his Pittsburgh office, “has always been the domain of wise guys from the wrong side of the track.” Perhaps more than anyone else, Benter has changed that perception – among the tiny population of people who gamble for a living, that is.

By the time he moved back to Pittsburgh, Benter had inspired others in Hong Kong to form syndicates of their own. In response, the Jockey Club began publishing reams of technical data and analysis on its website to level the play­ing field. With a little effort, anyone could be a systematic gambler – or mimic one. The odds boards at Happy Valley and Sha Tin were colour-coded to show big swings in the volume of wagers on a horse, specifically to reveal which horses the syndicates were backing.

The robo-bettors’ numbers have continued to proliferate. After Woods’ death, his children maintained his Hong Kong operation, but other members of the team went into business for themselves. And Benter spread the secrets of his success in various ways: he gave maths talks at universities, shared his theories with employees and consultants, and even published an academic paper laying out his system. The 1995 document – “Computer-Based Horse Race Handicapping and Wagering Systems: A Report” – became a manual for an entire genera­tion of hi-tech gamblers.

Digital age presents new opportunities for Hong Kong racegoers

Today, online betting on sports of all kinds is a US$60 billion industry, growing rapidly everywhere outside the US, where the practice is mostly banned. The US Supreme Court, however, may lift federal restrictions this year and, if it does, American dollars will flood the market, increasing liquidity and the profits of computer teams.

Big names from the world of finance have taken notice. In 2016, Susquehanna International Group, an American quan­ti­tative trading company, started an Ireland-based operation called Nellie Analytics Inc, targeting basketball, American football, soccer and tennis. Phoenix, a proprietary sports-betting company with headquarters in Malta and data-mining operations in the Philippines, won a US$13 million investment in 2010 from a unit of RIT Capital Partners PLC, the multibillion-dollar trust chaired by Lord Jacob Rothschild of the global banking dynasty. (RIT sold its stake in 2016 to a private buyer, quadrupling its money.) What is not widely known is that Phoenix was founded by former employees of Woods, including protégé Paul Longmuir.

Many of the biggest players in sports betting can trace a lineage directly to the Benter-Woods axis.

The Australian press, for example, has called Zeljko Ranogajec “the world’s biggest punter”. Today he runs a global algorithmic gambling empire, but he began his career in Las Vegas, counting cards with Benter and Woods, then followed them to Hong Kong. During a rare interview in London, Ranogajec said, “A substantial portion of our success is attributable to the pioneering work done by Benter.”

Benter has few regrets. One relates to an attempt in the early 90s to create a model for betting on baseball. He spent three summers developing the system and only broke even – for him, a stinging professional defeat. America’s pastime was just too unpredictable.

That failure, however, led to a second period of his career as lucrative as Hong Kong was. He worked with one of his baseball backers to start betting on US horse racing. Pari-mutuel tracks are scattered around the country, and by the late 90s it had become easier to amass data on many of them.

The US business took off just as competition began eroding profits in Hong Kong. “There is a golden age for a particular market,” he says, fiddling with a stack of decommissioned casino chips. “When there aren’t many computer players, the guy with the best system can have a huge advantage.”

In 2010, Benter married Vivian Fung, whom he had met at the Rotary Club in Hong Kong. The couple have a young son, and Benter seems in every sense a contented man. An active philanthropist, he donated US$1 million to a Pittsburgh char­ter school programme and US$3 million to a polio immuni­sation effort in Afghanistan, Pakistan and parts of Africa.

In 2007, he started the charitable Benter Foundation, which makes donations to support health, education and the arts. Many of those he meets at fundraising galas and nights at the opera have no idea how he made his money.

And how much is that, exactly?

During our interviews, it is the one topic that makes him visibly uncomfortable. William Ziemba, a finance professor at the University of British Columbia who studied the Hong Kong syndicates, has said that a first-rate team could make US$100 million in a good season. Mathematician Thorp (who is still writing about gambling in his 80s) asserted in a 2017 book that Benter had a “billion-dollar worldwide business betting on horse races”. When pushed, Benter concedes that his operations have probably made close to US$1 billion overall, but that some of the money has gone to partners in Hong Kong and the US. “Unfortunately,” he says, “I’m not a billionaire.”

Thirty-two years after he first arrived in Hong Kong, Benter is still betting on horses at venues around the world. He sees the odds change in the seconds before a race as all the computer players place their bets at the same time, and he is amazed he can still win. He continues to tinker with his model. The latest addition: how much does moving to a new trainer improve a horse’s performance?

Benter also runs a medical transcription company, but it is only modestly profitable. “I find the real business world to be a lot more difficult than horse racing,” he tells me. “I’m kind of a one-trick pony.”

Text: Bloomberg Businessweek

Additional reporting Jonathan Browning and Giles Turner