Gregg Popovich steps down as San Antonio Spurs head coach after 29 seasons; ESPN’s Shams Charania reveals the key reason behind the decision.

Gregg Popovich's career as the Spurs' head coach has ended after 29 seasons. Here's his historic coaching career by the numbers.

Gregg Popovich understood the world. That goes back long before the basketball world knew who he was. It probably can be traced to at least Popovich's time at the U.S. Air Force Academy, where he majored in Soviet studies and was on his way to becoming a spy. He became an icon instead.