Ungar was known as the sharpest card-player in the business, a legend in his own lifetime. But, like all Las Vegas legends, he was destined to finish badly. He went out sordidly, stupidly, wastefully. Exhausted by years of drug abuse and the batterings of a town that loves to reward a winner all the better to rob him blind, he checked into a cheap hotel on the lower end of Sunset Strip and never checked out again.
His pale, emaciated body was found face up on the bed where he had lain, miserable and alone, for two days and two nights of delirium and despair - the ultimate Lost Weekend. He had no possessions with him apart from $800 in cash. It was all that he owned in the world.
Las Vegas is the sort of place that chews up people like Stu Ungar and spits them out again with no more than a twinge of conscience. For 20 years Ungar negotiated the rapids of the most tantalising and most dangerous city in America, with more naivety than cunning. Pushed out of most card games because he kept winning, he was forced into the highest-stakes contests, particularly a poker variant called Texas Hold 'em, where winnings, and losses, are reckoned in the millions.
In his drive to win tournament after tournament, Ungar also became hooked on drugs, on the shady money-men who kept him solvent, on the game for the game's sake. Even when he was not playing cards he could not restrain his impulse to gamble, throwing away his fabulous winnings almost as soon as he had earned them on horses, or football games, or any other book in town.
His was a life of dependency - dependency on the hotels and flophouses that were the closest thing to home he ever knew, dependency on the cocaine that kept him on the sort of highs that even Las Vegas could not provide, dependency on the friends and associates who pushed him in the direction best served by their own interests, not his.
He lived as long as he did - he died at 45 - perhaps because he did not fully understand the implications of what was going on around him.
"He did not understand much about anything except poker," said the former hotel casino owner Bob Stupak. "Stu wouldn't know how to pay an electricity bill. I don't even know if he had a driver's licence."
The stories about Ungar are as touching as they are crazy. In 1980 he was invited to play at an international tournament in Ireland, but he did not have a passport. When he went to the passport office he was told he might have to pay a little extra to get his application processed in time for his departure. Without flinching, Ungar pulled out a roll of 100-dollar bills. "That's what Stu thought the guy meant by a few extra dollars," Stupak recounted.
On another occasion, Ungar decided it was time to buy a car. So he went to the fanciest car dealership in Las Vegas and bought a top-of-the- range Mercedes - in cash. For a year he gunned around town beaming with pride, until one day he ground to a halt on the highway. A mechanic later told him he had burnt the whole thing out because the oil sump was empty. "Why the hell didn't they tell me you had to put oil in the car?" he demanded.
His daughter Stefanie, now 16, remembers visiting him and seeing a discarded letter from President Bush inviting him to the White House. "I asked Dad if he was going to go and he said No. I said, `Dad, you know how rare it is to get an invite to the White House?' He said: `What would I talk to the President about? We have nothing in common'."
For all the Vegas glitz that Ungar became part of, he never strayed far from his roots as the son of a bar-owning bookie on New York's Lower East Side, traditionally the roughest neighbourhood in Manhattan. When he was 10, Ungar gained his card apprenticeship on holiday in the Catskill mountains, learning gin rummy from the waiters at the hotel where his family was staying, then beating them at their own game. When he was 13 his father died and a year later his mother was paralysed by a stroke, forcing him to drop out of school to live on his wits.
Ungar gravitated towards the only world where he could use his skills, learning how to win thousands of dollars in poker clubs frequented by mob members. In one gin rummy session he won $10,000, only to blow it at the races a few days later.
Fabulous winnings and even more fabulous debts succeeded one another with ever more demonic speed until, in 1978, Ungar hot-footed it to Las Vegas to escape the wrath of a bookmaker to whom he owed tens of thousands of dollars. Almost immediately, he won the $50,000 first prize in a gin rummy competition, enabling him to clean his slate and start afresh - although Las Vegas's first act was to ban him from the game he played so well.
Nevada brought Ungar face to face with the twin demons in his life: Texas Hold 'em and cocaine. The former turned him into an overnight sensation when he won the World Series of Poker on his first attempt in 1980 and then held on to his title the following year. He was nicknamed The Kid, partly because he was so young - 27 at the time - and partly because of his diminutive height (just 5ft 5in) and boyish looks.
The cocaine started out as an emblem of his success, but was to prove his undoing. Ungar had married a waitress he had met in a New York club and the couple produced a daughter in 1982. But their happiness was short- lived. His cocaine consumption was so excessive that it destroyed his nostrils, forcing him to wear blue-tinted granny glasses to conceal spaced- out eyes and ravaged nose. "I did coke to keep up," Ungar explained in an interview with the New York magazine Icon a few weeks before he died. "You use it as an excuse to stay up and play poker. But then you take it home with you..." The drug habit also brought him dangerously close to Mafia enforcers, who both sold him the drugs and lent him money to tide him through his barren patches.
His contacts included the legendarily violent Tony Spilotro, another notoriously short man, nicknamed "The Ant", whose lightly fictionalised counterpart was played by Joe Pesci in Martin Scorsese's movie Casino. It wasn't a comfortable relationship, but Ungar kept winning just enough to avoid retribution.
As the years passed and his highs and lows became ever more volatile, Ungar won no fewer than 10 major no-limit poker titles. He also found himself with stomach ulcers and colitis. At one competition in 1991, he played with a tooth abscess and a high fever. By the mid-Nineties, he seemed to have dropped out of the sport altogether - a sad genius whose talents had gone to seed.
But there were still a few people who believed in Ungar, and in 1997 they backed him to victory in his third World Series championship. "That was by far my greatest performance ever," a stunned Ungar said after he had beaten off the challenges of 300 rivals to win $1.1m.
In May 1998, Ungar was all set to defend his title, but he was so ill that he never left the 12th-floor hotel room in Binion's casino, venue of the competition. He had blown his million in two months and was back to binge drug-taking, mostly smoking crack cocaine through a pipe now that his nose was long gone.
Bob Stupak was the last in a long list of sponsors who believed Ungar could still be turned around. Two days before his death, the two of them did a deal whereby Stupak assumed his debts and agreed to act as his manager. He also gave Ungar $2,000 in "walking around money" to tide him over.
On the fatal weekend, Ungar was supposed to be with a minder provided by Stupak, but he gave him the slip, saying he was taking his daughter out for a birthday treat. After his first night at the Oasis Motel, a bellhop found him shaking furiously on his bed. After his second night, the same bellhop found him dead.
"He was the best," Stupak said after the discovery of Ungar's body. "You can't expand on that." The best, however, in an unforgiving world that never sought to understand Stu Ungar, eventually sucked the talent out of him, and let him die the most frightening and lonely of deaths in a Las Vegas dive.