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Donnie Walsh is one of the most accomplished NBA executives of the past several decades. He turned the Indiana Pacers into a consistent winner and even built the only New York Knicks roster to win more than 50 games this century. But after a career spanning almost 40 years, Walsh has announced his retirement from professional basketball in an interview with Matthew VanTryon of The Indianapolis Star.

"I'm getting older and don't have the energy," said Walsh, 79. "It's a young man's sport. This job has always occupied a great deal of my time. The Pacers were always in my head. This gives me an opportunity to pay attention to my children, my grandchildren and my wife (Judy) of 58 years."

Walsh joined the Pacers in 1984 and became their general manager in 1986. They missed the playoffs only five times over the next 22 seasons under Walsh's stewardship, and with one of his first draft picks in Reggie Miller leading the way, they consistently contended for championships. They fell two games short during the 1999-2000 season, though, and never made it back to the NBA Finals. 

In 2008, Walsh left the Pacers to take on one of the NBA's greatest challenges: resuscitating the New York Knicks. He very nearly succeeded in doing so, spending several years clearing cap space for the free-agent frenzy of 2010 and recruiting Amar'e Stoudemire with that space. That helped him land Carmelo Anthony through trade, and suddenly, the Knicks had the foundation of their 54-win 2012-13 roster. 

He didn't get to see his project through, though, as he resigned in 2011. His replacement, Glen Grunwald, prematurely used New York's amnesty clause on the expiring contract of Chauncey Billups in order to chase Tyson Chandler in free agency. That deprived the Knicks of the cap flexibility they needed to pursue Anthony's close friend, Chris Paul, a year later, and as a result, the Knicks never improved upon that 54-win season. 

He returned to the Pacers for a brief stint as president of basketball operations after Larry Bird stepped down, but has largely worked as a consultant to the team ever since. Now, he retires as one of the winningest executives in basketball history. He may not have a championship ring, but he took both of his teams closer than they've come before or since. That may one day be enough to get him into the Hall of Fame.