LOS ANGELES - When Kobe Bryant joined the Lakers and Paul Pierce landed with the Celtics in the late 1990s, they both learned most of what they needed to know about their franchises' histories and expectations simply by looking at the forests of fabric high above the court.

These teams only hang banners for championships, and they're usually in big groups.

Multiple titles are the only metric of success, the only validation still interesting to Bryant and Pierce. Bryant is trying to accomplish the rarest of NBA feats for the second time in his career, while Pierce's Celtics get their first chance when the NBA Finals begin Thursday night at Staples Center.

"It's going to mean everything for my career, because a lot of guys have won one, and not many have won a couple," Pierce said Wednesday.

Pro basketball's most successful franchises are together in the NBA Finals for the second time in three years and the 12th time overall. These teams will have won 33 of the league's 64 titles when they finish a potentially fascinating series with plenty of modern subplots.

"We're always focused on winning a championship," Bryant said. "And when you do it, you want to do it again and again."

Bryant is enjoying a dynamic postseason despite hobbling through injuries during a third straight Finals run by his remarkably steady Lakers, who are 8-0 at home in the playoffs and haven't even trailed in a series.

Boston's rise from a 50-win regular season as a No. 4 seed has been even more surprising, with Rajon Rondo making a quantum leap into stardom during what might be the last stand for Boston's Big Three of Pierce, Kevin Garnett and Ray Allen.

But on the biggest scoreboard of all, the one these players claim they seldom check, it's Celtics 17 titles, Lakers 15. Don't expect fans in either basketball-crazy city to forget that score when their team takes it all again.

Only nine NBA teams have won more than one title, and just five franchises besides the Lakers and Celtics repeated as champions within the same half-decade.

Allen got a perspective on the achievement from no less an authority than Michael Jordan during a conversation last week.

"He told me, 'The first one you win, you're lucky," ' Allen said with a grin. "I didn't win six, so I don't know what it feels like to be able to do it that many times. . . . It adds to your [legacy] to be able to be here and say that you won multiple times."