Booed by the locals, beset by officials and berated by former mentor Rick Pitino, Antoine Walker was at a crossroads. The Celtics had just taken Paul Pierce, a forward with a knack for scoring, with the No.10 pick in the '98 draft, leaving Walker's role in Boston unclear. Wanting an early read on his new teammate, Walker traveled to LA to play a little pickup with Pierce. "You always have to test and see what type of person you're getting," Walker says.

Walker learned two things that day. One, Pierce wasn't some chill kid from LA. He responded to Walker by talking as much smack as Antoine could handle. "Paul's a guy who will get in your face," says Walker. "He's going to give it to you brutally honest." The second lesson: The kid could play. Instead of a rivalry, a partnership was born.

Friendship came first. That helped, since both needed someone to lean on. It wasn't just the losing, either. Two years ago, Walker was robbed at gunpoint on Chicago's South Side, and Pierce helped him get over that. Then Pierce was stabbed at a Boston nightclub in the fall of 2000, and Walker was there for him. Celtics GM Chris Wallace now likens the co-captains to inseparable twins. Besides palling around in their down time, the two share a program -- known as Pierce's Playground and Walker's Way -- that invites underprivileged kids to each Celtic home game.

The two have clicked on the court the past two seasons under coach Jim O’Brien. The first Celtic since Larry Bird to achieve back-to-back 2,000-point seasons, Pierce has enough power to slice or spin his way to the hole, but it's his shooting touch (40% from three, 44% overall) that makes him so dangerous. At 6'9", 245 pounds, Walker plays like a point forward in a power forward's body. His ability to handle the ball and shoot the three draws bigger defenders away from the basket and frees Pierce to operate. "I like passing the ball," says Walker.

Especially to Pierce.

This article appears in the April 29 issue of ESPN The Magazine.