As the NBA season heads into Week 3, the “experts” on ESPN are backing the Boston Celtics, saying they’re going to repeat. And why not? The Celtics return all their returning starters, including the “Big Three” of Ray Allen, Kevin Garnett and Paul Pierce, and Boston coach Doc Rivers himself admitted to picking the Celtics to win the 2009 title.

But that’s not the point. Even if the Celtics didn’t have all their returning players, it’s a good bet ESPN would have them playing into mid-June, simply because they’re coming off an NBA Championship.

It has to do with inertia–the force that resists change. The Celtics, no different from any other team coming off a championship season, have left good memories in sports fans’ minds, and cause people to employ the “if they won last year, they’ll win again this year” mentality.

Before the NBA season started, and especially now that Boston is off to a 7-1 start, sports analysts are going with the safe pick, the pick that won’t get them fired. Boring. Even someone who doesn’t follow the NBA can make an educated assumption that if a team won last year, they’re probably still pretty good and have a chance at repeating.

Why not the Miami Heat, a team that drafted No. 1 overall pick Michael Beasley, acquired Shawn Marion from the L.A. Clippers and returns a healthy Dwayne Wade? Or what about the Portland Trail Blazers? Sadly, when talking in front of millions of sports fans on national TV, so-called “sports experts” aren’t bold enough to say a team like the L.A. Clippers, who were 23-59 last year but signed proven winner Baron Davis over the offseason, will reach the playoffs.

Recent history has proved that inertia is difficult to maintain, and that winning consecutive championships in current times is not an easy task. The NBA hasn’t had a team win back-to-back titles since the Lakers won three straight from 2000 to 2002. Baseball has had seven different World Series champions in the last eight years, and the New England Patriots are the only NFL team to win back-to-back championships since 1999.

The current season, however, could be not only be an exception in the NBA, but also in the NFL. The New York Giants are trying to validate the theory of sports inertia, as they head into Sunday’s match-up with the Baltimore Ravens looking to improve to 9-1. Eli Manning has proved that his strong showing in last season’s playoffs was not a fluke, and Brandon Jacobs has emerged as one of the best running backs in the league. The defense is strong, and there’s no reason to think they won’t be back for Super Bowl XLIII in Tampa.

And the Boston Red Sox, who won the 2007 World Series, advanced all the way to the seventh game of the American League Championship Series against the Tampa Bay Rays in 2008, doing so despite losing 12-time All-Star Manny Ramirez to the Los Angeles Dodgers in July and Mike Lowell to injury.

The Celtics could very well be next. Only eight games into the season, they have already established themselves as the team to beat in the Eastern Conference, and it’s hard not to see them playing for their 18th NBA title.

But please ESPN, spice it up, be brave, go out on a limb and pick the underdogs to win. Obviously the Celtics are good–they won the whole thing last year. But what about those Memphis Grizzlies? Okay, maybe a stretch, but you probably would have laughed if someone told you the Tennessee Titans would be 9-0 heading into Week 11.