In many ways, the 1999 and 2012 lockout seasons are bookends in NBA history.

Michael Jordan’s second retirement effectively ended an era. With his Chicago Bulls dismantled, none of the great teams from the late 1990’s were able to win a championship in the 2000’s. In the first postseason following the 1999 lockout, a San Antonio Spurs team featuring a 22-year-old Tim Duncan went 15-2 en route to their first championship.

Over the next 13 years, the Spurs became the NBA's gold standard, missing the second round of the playoffs only twice. The 2000's were a golden age of skilled 7'0 (Tim Duncan, Kevin Garnett, Shaquille O'Neal, Dirk Nowitzki), and that quartet won 10 championships while appearing in 12 of 13 NBA Finals.

In his prime, Duncan was the most complete player of the four, capable of dominating offensively on the low block (unlike Garnett), moving his feet defensively (unlike Shaq) and anchoring an elite defense (unlike Dirk). The Spurs won three titles between 2003-2007 and were only inches away (Derek Fisher's 0.4 shot in 2004, Dirk's and-1 in 2006) from five in a row.

Five years since their last title, San Antonio still has many of the same players, but their identity has changed. With Duncan lacking the athleticism to dominate defensively, they've become an offensive team built around ball movement and jump-shooting.

And after five games in the Western Conference Finals, one thing is clear: if Kevin Durant, James Harden and Russell Westbrook can get to the rim, there's no one on San Antonio’s roster who can stop them from finishing. Several times in Game 5, Duncan could do nothing but try to take a charge as the Thunder's young stars contorted in the air around him for a layup.

The Spurs, once one of the fiercest defensive teams in the NBA, have resorted to tricks and gimmicks on that side of the ball. Like the Sacramento Kings and Dallas Mavericks teams of the early 2000's, San Antonio works the refs relentlessly, grabbing, holding and flopping in an attempt to make up for their inability to stay in front of more athletic teams.

The Twin Towers are a distant memory in Central Texas, as Gregg Popovich fielded small-ball lineups that would have made Don Nelson proud throughout Game 5. The Spurs played large stretches of the game with one big man and four perimeter players; at one point, they had Dejuan Blair at center and no one above 6'7 on the floor.

Popovich has reenacted Pat Riley's career journey, from the Showtime Lakers to the clutch-and-grab New York Knicks, in reverse. His teams have gone from playing a halfcourt oriented defensive system to a free-flowing, fast-paced offensive one, an evolution that has mirrored the league's as a whole, now that the first generation of players who grew up in the post-Jordan have begun to take over the NBA.

But while San Antonio has done their best to adapt to the new era, Oklahoma City has a chance to define it. The Thunder, without a low post scorer or a frontcourt player capable of creating their own shot, run their offense through the perimeter, with three young stars sharing the spotlight and the ball.

They've already defeated Dirk's Mavericks and Kobe Bryant's Lakers this postseason, and now they have Duncan's Spurs on the ropes as well. It hasn't been easy, as their reliance on one-on-one plays that start from the three-point line leaves them vulnerable to offensive droughts and turnovers, none more jaw-dropping than two miscues on inbound plays in the final minutes of Game 5 that kept San Antonio alive.

But while their youth almost cost them, it's still been a huge edge for them in this series. Kevin Durant played 43:17 while Russell Westbrook played 44:37 on Monday; in contrast, Tony Parker played 40:53, Manu Ginobili played 38:26 and Duncan played only 33:09. Matching up your stars with the opposing team's bench players for a few minutes can be the difference in a close playoff game, something both the Heat and the Thunder have taken advantage of in the Conference Finals.

To keep his chances at a fifth championship alive in a do-or-die Game 6, Duncan will need to match the endurance of players who were in middle school when he entered the NBA. He was present at the beginning of an era, and unless he can turn back the clock in Oklahoma City, he'll be there at the end as well.