The San Antonio Spurs come into the Western Conference Finals on a historic tear, with a 29-2 record in their last 31 games. But while their ability to demolish the Utah Jazz and Los Angeles Clippers isn’t unimpressive, it only tells us so much about how they will match up with the Oklahoma City Thunder.

In the NBA playoffs, momentum is fairly ephemeral. A large portion of a player’s performance depends on who they are defending and who is defending them; how they played against a different opponent the week before only has so much predictive value.

In 2010, the Orlando Magic rampaged through the first two rounds of the Eastern Conference playoffs, sweeping the Charlotte Bobcats and the Atlanta Hawks while looking like the best team in the NBA. But in the Eastern Conference Finals, they ran into a Boston Celtics squad with the personnel (Kendrick Perkins, Rasheed Wallace) to defend Dwight Howard 1-on-1 without needing to double team off the Magic’s shooters.

The year before, the shoe was on the other foot, as Orlando was the underdog against a Cleveland Cavaliers team that seemed unbeatable. Before the 2009 ECF, Cleveland had a 66-16 regular season record and a +8.9 point differential, winning their previous eight playoff games by at least ten points. However, none of that mattered when they had to defend Howard with Zydrunas Ilgauskas and Anderson Varejao.

In breaking down an NBA playoff series, you can throw away the storylines and how each team has performed against the other 28 NBA teams. All basketball games begin with matchups, and understanding a series starts with breaking down who is guarding whom.

Perhaps the most intriguing individual matchup in the Western Conference Finals is at the point guard position, which features Russell Westbrook and Tony Parker, the two All-NBA second team guards. One storyline to watch will be how much each starting point guard sees of each other defensively, as both teams play long 6’6+ swingmen (Thabo Sefolosha and Danny Green) who often get the most challenging defensive assignment on the perimeter.

Westbrook, one of the NBA’s best athletes at 6’3, 190, has dramatically improved his offensive efficiency from last season’s playoffs, averaging 24.4 points, 5.0 rebounds and 4.5 assists on 47% shooting. Most importantly, he’s cut down on his turnovers to only 1.5 per game. Parker, meanwhile, has become the Spurs primary offensive option, averaging 19 points and 3.0 rebounds on 48% shooting while handing out seven assists on three turnovers per game.

Against either Sefolosha or Westbrook, Parker won’t have his typical athletic advantage on his initial perimeter defender. As a result, San Antonio will probably run a lot of pick-and-rolls to free up Parker and test Oklahoma City’s defensive rotations. In many ways, the veteran Spurs, with skilled shooters and passers at nearly every position of the floor, represent the ultimate test for a Thunder team that too often uses their athletic advantage to cut corners defensively.

On the other end of the floor, Oklahoma City’s perimeter athleticism will test San Antonio’s team defense in ways that the Clippers or the Jazz could not. The Thunder have three different players (Westbrook, Harden and Kevin Durant) who can get to the front of the rim, and Tim Duncan doesn’t have the quickness to challenge and recover to his man like he once did.

As a result, San Antonio will likely try to copy the defensive adjustment Lakers head coach Mike Brown made in the second round: keeping Kendrick Perkins and Serge Ibaka’s men in the lane and daring the Thunder’s big men to score from the perimeter. Ibaka’s improving jumper has been one of the under the radar factors for Oklahoma City’s ascension, but Perkins’ lack of offensive ability could be exposed in this series.

That’s why the most intriguing adjustment Scott Brooks can make is going small, with Ibaka at center and Durant at power forward. None of the Spurs other big men (Boris Diaw, Matt Bonner or Tiago Splitter) have the post game to punish Durant in the low block, which could force Popovich to go small as well next to Duncan.

With Parker/Westbrook and Harden/Ginobili likely a draw, San Antonio’s best chance of winning the series is Duncan, who will need to outplay Ibaka in the low post. Durant is the key player for Oklahoma City, as the Spurs don’t have an obvious matchup for his combination of size and speed. The 33-year old Stephen Jackson no longer has the foot-speed, which leaves Green (too short) and rookie Kawhi Leonard, an athletic 6’7 225 combo forward with a 7’3 wingspan.

For the first time in his young career, the spotlight and the pressure will be squarely on Durant’s shoulders. My guess is he’s ready, which is why I’m picking the Thunder to win in six games.