It’s widely assumed that the Cleveland Cavaliers’ best asset in their upcoming NBA Finals series against the San Antonio Spurs is forward LeBron James. He is universally regarded as one of the game’s top two or three players, and his Game 5 performance in the Eastern Conference Finals — where he scored 29 of his team’s last 30 points in a double overtime victory — has raised his stature to that of a legend.

If the Cavs win it all, it most likely won’t be completely because of James (though I don’t want to discount the prospect that he will go off for two weeks like Dwayne Wade did last spring). No, if the Cavs win — and I think they can — it will be because of their coach, Mike Brown.

Stop giggling, I’m serious. As John Hollinger pointed out yesterday in this space, the Cavaliers were built with the Spurs as a model. Team president Danny Ferry came from the Spurs organization and one of his first hires was Brown, who was a Spurs assistant for three seasons and coached their summer league teams. It’s also worth noting that the Spurs are one of the most statistics-savvy teams in the NBA, and Ferry chose to duplicate that aspect of the San Antonio approach, hiring stats guru Dan Rosenbaum.

The Cavs are one of two teams to adapt the San Antonio way; Dallas is the other (and there will probably be a third if some team with a coaching vacancy makes the Spurs’ assistant coach, P.J. Carlesimo, an offer he can’t refuse this summer). And just as the Jeff Van Gundy Knicks usually beat Pat Riley’s Heat, protégés have a good track record against the mentor when it comes to San Antonio coach Gregg Popovich. Dallas has won nine of the last 15 against the Spurs and eliminated them in last year’s playoffs. As coach of the Cavs, Mike Brown has won three of four against Popovich.

Fifteen and four games are an awfully small sample size but some trends emerge. The Cavs are built as a good rebounding team. They corral 29.7% of all available offensive rebounds, which ranks them third in the league at creating extra possessions. They also clean the defensive glass at an excellent rate, preventing an additional possession 75.8% of the time, good for second best in the league. This is crucial. Since San Antonio plays suffocating defense, it will be important to have extra possessions, and you want to limit the Spurs to one shot per possession as often as possible. The Cavs were also among the top teams in creating turnovers and taking care of the ball. This is a steep uphill climb, and they will need to be as efficient as possible.

Another factor will be defending the 3-point line. It’s well known that the San Antonio defense pays special attention to choking off the longball. However, the San Antonio offense makes great use of the shot from behind the arc. They are third among teams in the playoffs, attempting 19.6 shots a game from downtown. They also hit a postseason-leading 39% of them. This plays into a strength of the Cleveland defense, which took away that weapon from Detroit, another trey happy team, in the Conference Finals. The Cavs rank third in defending the longball, allowing only 32%.

When measured by points per 100 possessions, Cleveland is the fourth best team in the NBA and the Spurs are second. Overall, if Cleveland implements a quality defensive gameplan, then this figures to be a tight, low-scoring series. If it is, then that’s where the importance of James comes in. Bruce Bowen will guard James as he has in the four previous matchups in the Mike Brown-era, but given LeBron’s recent success, Popovich may want to consider a double-team every now and then. In those four games, James has averaged 29.5 points a game and shot 51%. Of course a double-team could leave them vulnerable to Daniel Gibson’s outside shooting, presuming that his Detroit mojo is still working.

Other Cleveland X-factors include the health of guard Larry Hughes. If his foot injury has healed a bit his length could bother Spurs point guard Tony Parker. Also Sasha Pavlovic needs to play under control. His twisting, spinning shot attempts during “the Le-Bron game” made a solid argument for just letting James go one on five if necessary. Last, reserve pivotman Anderson Varejao will need to stay out of foul trouble as he will be Cleveland’s most effective defender against Tim Duncan.

The Spurs are heavy favorites in this series, and they should be. Their winning percentage and point differential argue that they are far superior to Cleveland, but this series isn’t about 82 games against a myriad of opponents, it’s about a best of seven between these two. And thanks in large part to Cleveland being modeled after San Antonio, the Cavs are poised to shock the sports world.

mjohnson@nysun.com