It comes every spring – the sense of eagerness for a new beginning, or the feeling that change is in the air. Basketball fans in particular have a designation for the eagerness and elation that they feel: March Madness.

That moniker of course is synonymous with the NCAA tournament – perhaps America’s single greatest sporting event, which tipped off yesterday afternoon. So what of the NBA? Is there not mayhem and fervor afoot in the pro ranks of this beautiful sport?

Aye keen observer, there is: with the playoffs right around the corner and a landscape-changing free agent class coming to the market this summer, the anxiousness felt by many NBA clubs is palpable.

But this spring in particular brings a unique sense of distortion in the NBA’s scenery which extends beyond the usual eagerness for draft prospects and free agent hopes. Certainly team executives from New Jersey to Minnesota (and everywhere in between) will be caught up in the John Wall Showcase Sweepstakes otherwise known as the NCAA tournament, laying in hope that a transformation might come to their franchise.

But for others, a real permutation of sorts has already occurred. There has been an recognizable changing of the guard atop the NBA standings. The old classicists of the old established order – the San Antonios, the Phoneixs and the Bostons of this world – have begun to die out.

These powers that be have been the ruling class of the league for at least the last half decade, or in San Antonio’s case even longer. But those in the old line have been replaced in our hearts, and in the standings by a new, fresh crop of teams ready to take their place in the pecking order of the NBA elite.

The first and most obvious team now ascending Olympus is Oklahoma City. The Thunder have won 8 of their last 10 games to rise all the way to fifth in the Western Conference, only two games back of the incumbent Utah Jazz. When a team’s starting lineup has an average age (23.2 years) almost in line with their win total at the All-Star break, some kind of youth revolt is definitely taking place. Surprisingly for being a young team, much of their success and be attributed to their defense, not offensive explosiveness (they rank third in the NBA in Opponent Field Goal Percentage, and 10th in Point Differential).

Of course one would be remiss to not focus as well on the rise of their young leader Kevin Durant, who this season has gone from terrific prospect and future All-Star to a bonafide franchise player. A strong case could be made that he already, at all of 21 years of age, is the third best player in the league: his 29.7 points per game average, his 7.5 rebounds a night, a field goal percentage just under .500, and a range on his jumper that is unrivaled all build arguments for themselves.

Durant is not alone though certainly. Following an excellent rookie campaign, Russell Westbrook has emerged as more than just a exciting combo guard, and has elevated himself into the discussion for the best young guard in the league. He has done so by showing other-worldly athleticism and quickness while putting up a cool 16.8 points, 5.1 rebounds, and 8.0 assists a night.

Westbrook, along with supporting pieces such as Jeff Green, James Harden, and Thabo Sefolosha, make up a nucleus of young supporting talent that is in a class of its own. Paired with Durant’s once-in-a-generation skillset, this group has greatness not just in its future, but its present as well.

The other team so often handcuffed to the Thunder when discussing rising young powers are the Trail Blazers. It was only a year or so ago that people in most NBA corners felt that Portland, not Oklahoma City, had set itself up to be the model franchise for the next decade. What can be said with great certainty is that Portland has acquired a pool of young talent that is the envy of almost the entire league. Now if only they could get them healthy.

The Blazers have also won eight of their last 10 games, and currently sit in eighth in the West, but the standings can appear deceiving at first glance – while Portland is currently the last team into the playoffs, they are only a game and a half back of the Thunder for fifth, and could conceivably still finish as high as fourth.

Coming into this season such a high finish may have been the expectation of the young Blazers, however no team anywhere has faced the type of injury problems they have. Injuries have hobbled this young squad: Nicolas Batum and Rudy Fernández both began the season on the inactive list, their star-crossed center Greg Oden suffered another season-ending knee injury, his backup Joel Przybilla soon followed suit with a season-ending injury himself, all LaMarcus Aldridge battled ankle problems and team leader Brandon Roy played through shoulder and hamstring issues.

In the face of that laundry list of aliments, the Blazers have endured, and in fact are now thriving. Even with the recent addition of 35-year-old Marcus Camby, the team’s average age remains only 25.8, which places them amongst the lowest in all the league. Possessing one of the NBA’s best young leaders in Roy, a multi-talented and versatile big in Aldridge, and one of the deeper benches in the league, the Blazers remain poised to make a playoffs run this season, and are certainly establishing themselves as a permanent postseason fixture out West.

The third team to consider as a part in this youthful uprising is Atlanta. The Hawks have now made the playoffs two year running, and last year boasted their first winning season in nearly a decade. A direct line can be drawn between that success and the ongoing maturation of their young core roster.

While the team’s overall average age of 26.9 is actually above average, that metric is skewed by the considerable age of some of their role players. The Hawks depend mightily on the speed, dexterity and athleticism of their starting frontline – Josh Smith (who is 24), Marvin Williams (23), and Al Horford (23). Without their young energy, Atlanta would not be in the position they are now, which sees them tied with the old-guard Celtics for third in the East.

And what of that old guard? How did those well-seasoned veterans age so rapidly? In reality, they knew this was coming. The respective front-offices of the perennial contenders in Boston and San Antonio went out last summer and acquired pieces (for Boston, Rasheed Wallace; for San Antonio, Richard Jefferson) that they felt could push them over the top for one more charge to greatness.

Unfortunately though, those moves failed to pan out, and the expiration date on each of their title hopes is nearly up.

The Old Gods are still effective of course – even with less athleticism and mobility, they are built to play playoff basketball, where the game slows down and experience matters almost as much as execution. But they are also much susceptible to injury and fatigue. Boston’s average age now hovers at 29, while thanks to a young bench the Spurs still rest at 27 as their average age.

Even the Cavaliers, who appear to be the odds on favourite to win it all, are not without concerns related to aging. Shaquille O’Neal is already injured, and Žydrunas Ilgauskas has yet to return to the lineup. That means they will have limited time to get acclimated to one another, potentially hurting their team chemistry (though when you have LeBron James, these things seem secondary).

So in this spring season of fresh starts and new beginnings, we see a change in the NBA’s power dynamic. Systemic shifts have taken place this season that will bare out in the playoffs. And the league will be better for it – new teams and new hopeful fan bases are the lifeblood of this league.

As for the hopes of the Old Guard to overcome their fatigue and battle-worn bodies, they can build themselves up with the mantra of coaching legend Rudy Tomjanovich, who famously declared that you can “never underestimate the heart of a champion”.

That may still be true of their hearts, but what of their legs?

Yes, a new spring has sprung in the NBA, and the madness is just starting.