Marvin Barnes, one of basketball’s most talented and defiantly self-indulgent players, whose career dissolved in a haze of drugs and alcohol, died on Monday in Providence, R.I. He was 62.  The death was confirmed by Kevin Stacom, a scout for the Dallas Mavericks, who was a teammate of Barnes’s on the Providence College team that reached the Final Four of the N.C.A.A. tournament in 1973. Barnes, who had been drug-free for several years, had recently succumbed to his addiction again, Stacom said.  A first-team all-American at Providence who led the nation in rebounding in his senior year, the 1973-74 season, Barnes went on to play two seasons for the Spirits of St. Louis in the American Basketball Association and then four in the National Basketball Association after the rival leagues merged in 1976.  On the court, he could be close to unstoppable. A sinewy 6 feet 8 (or 6 feet 9, depending on the source) and somewhere between 210 and 230 pounds, he played power forward or center. A scorer as well as a ferocious rebounder, he was swift afoot, especially for a big man, with sure, quick hands, a potent move to the basket, and a sweet, feathery jump shot.  Rookie of the year in the A.B.A. in 1974-75, Barnes averaged more than 24 points and more than 13 rebounds a game in his two seasons in St. Louis. In the 1975 playoffs, he scored 41 and 37 points in the first two games against the New York Nets, who were led by Julius Erving (a.k.a. Dr. J), and averaged more than 30 points a game in two playoff series.  “The truth is that there were many nights, even when Dr. J was in the game, when the best player on the floor was Marvin Barnes,” the veteran sportscaster Bob Costas, whose first job out of college was announcing Spirits games on the radio, said in “Free Spirits,” a 2013 television documentary about the team.  But from the start, Barnes was one of sport’s most flamboyant problem children; his nickname, given by a teammate, was Bad News. By his admission, he started using drugs in his second season in the pros, and from then on his skills diminished and his life spiraled downward. From 1976 to 1980 he played for four N.B.A. teams, averaging 9.2 points and 5.5 rebounds per game.  He admitted snorting cocaine on the bench as a member of the Boston Celtics. After leaving the game, he spent many years in bad shape, reportedly living in California, Texas and Virginia, sometimes homeless, sometimes in prison.  Like Muhammad Ali, to whom he was sometimes compared, he was a joyous braggart who promoted his great gifts and then proved he had them. Like Ali, he wrote poems to his opponents — “There once was a doctor named Erving/Whose slam dunks were especially unnerving” — and like Ali, he had the kind of charisma that made more friends than enemies, even among those he disappointed.  “He’s a nice guy, a sweet guy, everybody likes him,” Donald Schupak, an owner of the Spirits, said in an interview with The New York Times in 1976. “He’s just totally unreliable. He’s probably in the top five players in basketball, talent-wise. In terms of value to a team, he’s probably in the bottom 10 percent.”  Both he and Ali had renegade spirits, but unlike Ali’s, Barnes’s could be both selfish and reckless. From high school on he had run-ins with the law; in college he attacked a teammate with a tire iron, was given a probationary sentence and was later sent to prison after he was caught at an airport with an unloaded pistol in his luggage, violating the terms of his probation.  At one point during his rookie season in St. Louis, suddenly unhappy with his contract, he vanished from the team, resurfacing days later at a billiard hall in Dayton, Ohio. On another occasion, after missing the Spirits’ flight from New York to Norfolk, Va., he chartered a plane, insisted the team pay the pilot, then walked into the locker room minutes before tipoff carrying a bag of hamburgers and wearing a mink coat over his uniform. Then he went out and scored more than 40 points.  Marvin Jerome Barnes was born in North Kingston, R.I., on July 27, 1952, and grew up in Providence, where he attended Central High School, leading the team to state titles and becoming what The Providence Journal called “the greatest basketball talent the city ever produced.” His recklessness was also on display at a young age. As a teenager, he and some friends commandeered a city bus, and Barnes was easily caught afterward because he had been wearing his letterman’s jacket with his name stitched on the front.  In 1973, he teamed with another Rhode Island basketball legend, Ernie DiGregorio, and led Providence to the N.C.A.A. tournament in St. Louis, losing to Memphis State in the national semifinal. In 1974 he was chosen in the N.B.A. draft by the Philadelphia 76ers, the second overall pick behind Bill Walton, but elected to play in the A.B.A. instead.  He was married and divorced twice. His survivors include his mother, Lula Barnes, and a sister, Alfreda L. Barnes-Robinson. He returned to Providence sometime after 2000 and, with the support of former owners of the Spirits, ran the Rebound Foundation, a nonprofit organization providing guidance for wayward youths. In “Free Spirits,” he explained his attitude as a young man.  “I got introduced to some drug dealers and I got real close with them,” he said. “They became like my family. I was living my fantasy, though. I always wanted to be a gangsta, a drug dealer, a pimp, a player, a hustler. I was, like, I’m gonna die young, die fast, gonna die quick, and I’m gonna have fun. That’s it.”  A version of this article appears in print on September 10, 2014, on page B16 of the New York edition with the headline: Marvin Barnes, Enigmatic Basketball Player, Dies at 62. Order Reprints|Today's Paper|Subscribe
Barnes helped Providence College reach the N.C.A.A. Final Four in 1973 and played in the A.B.A. and N.B.A.