The stat was staggering when I first heard it. The Celtics and Lakers have combined to win 30 of the NBA’s 61 championships. With Boston and Los Angeles opening the 2008 NBA Finals on Thursday, the two franchises are on the verge of yet another title.

That means that in approximately two weeks the two franchises will account for exactly 50 percent of all NBA championships. Half the teams in the league have never won a championship. To put the Celtics-Lakers domination into perspective, compare the two teams against the top two from the other major pro leagues:

• NFL
  The Dallas Cowboys, Pittsburgh Steelers and San Francisco 49ers each have five Super Bowl victories. Using any pairing, the top two NFL franchises account for less than 24 percent of all Super Bowl winners.

• MLB
  The New York Yankees lead the way with 26 World Series Championships, followed by the St. Louis Cardinals at 10. They’ve combined to win just under 35 percent of World Series in the modern era.

• NHL
  Dating back to 1926, when the NHL assumed control of Stanley Cup competition, the Montreal Canadians lead the way with 22 Stanley Cup Championships. The Toronto Maple Leafs have the second highest total with 13 Stanley Cups. The two teams come the closest, having won 43 percent of the NHL’s Stanley Cups. But even that number will dip slightly this year after Detroit or Pittsburgh wins the 2008 Stanley Cup

The Boston-L.A. stranglehold on the NBA Finals is equally impressive.

This is the 29th Finals appearance for the Lakers. They’ve won 14 titles. Their longest drought without a Finals appearance was nine years between their 1991 loss to the Chicago Bulls and 2000 victory against the Indiana Pacers.

For the Celtics, this is their 20th appearance. They’ve won 16 titles. This year’s berth ends their longest drought without a Finals appearance of 21 years.

Head-to-head, the Celtics are 8-2 vs. the Lakers in NBA Finals history, though Los Angeles won the last two meetings in 1985 and 1987.

Individual experience

The two franchises are steeped in NBA Finals tradition, but the players from both teams are much less familiar with the big stage.

Most of the Finals experience for the young Lakers comes from its starting backcourt of Kobe Bryant and Derek Fisher. The two helped the Lakers to 3-1 series record in the NBA Finals with the Lakers earlier this decade. Also, Luke Walton was a rookie on the 2004 Lakers team that lost 4-games-to-1 in the Finals against the Detroit Pistons. The only other Laker with Finals experience is Ira Newble, who saw limited action as a member of last year’s Cleveland Cavaliers. The Cavs were swept by the San Antonio Spurs.

The Celtics are a veteran-led team yet they have even less Finals experience. Their only Finals experience comes from their bench. Sam Cassell, who is playing only 13 minutes per game in the playoffs, won two titles with the Houston Rockets in his first two NBA seasons, 1994-95. Backup forward James Posey won a title with the 2006 Miami Heat. And Brian Scalabrine was a little-used member of the 2002 and 2003 New Jersey Nets teams that lost in back-to-back Finals appearances.

The Celtics Finals appearance is knocking several players off the list of “playoff games without a Finals appearance.” It took Kevin Garnett 67 games. It took 57 apiece for Ray Allen and Paul Pierce. For P.J. Brown, 100 games was the magic number. Now they’ll all contribute to the next chapter of the historic Celtics-Lakers rivalry.