When the Celtics take the floor at Staples tonight for game 7 of the NBA Finals, they will be doing so with hopes of capturing their NBA-best 18th World Championship, and their second title in the last three years. In order for the Green to accomplish their ultimate goal, they will simply need to be better.It is no secret that defense and rebounds win basketball championships. It is a fact of the NBA, it is the reason why the Celtics won the title back in 2008, and it is the primary reason why the Green got waxed Tuesday night in game 6. With Celtics center Kendrick Perkins likely limited for game 7, the Celtics reserves will certainly have their hands full.As has been the case throughout the Celtics’ entire playoff run, the Green will need first-time All-Star Rajon Rondo to get back to an elite level of play. Too often in these NBA Finals, Rondo has “settled” rather than do what he does best; force the tempo and keep the Lakers defense off-balance. Rondo has the ability to get his teammates involved with easy transition baskets; in transition there is no point guard better than Rondo. Unfortunately for the Celtics, too often in this series Rondo has been forced into half-court basketball, where he is simply average at best.Didn’t it have to be this way? This Finals is about the two best basketball teams on the planet playing one final game for all the glory, the “ultimate team” against the world’s best individual player.”It’s for all the marbles,” Kevin Garnett said. “If you can’t get up for this game, then stay home.”The good news for the Celtics is that there is no travel between games 6 and 7. While the players won’t use travel as an excuse, the truth of the matter is simple; the Celtics lost Game 1 after flying to LA, Game 3 after flying to Boston and Game 6 after flying back to LA.There is no expert, no writer, and no television personality who can accurately predict how game 7 will play out. There are simply too many variables. Throughout the course of this seven-game series both the Celtics and Lakers have found themselves on the brink with their backs against the wall, and both teams have responded with heroic efforts. Going into game 7 both teams now face elimination. The Lakers will face a disappointing Finals exit. The Celtics will potentially face the end of the new “Big Three” Doc Rivers era. Yes, there is a lot on the line for both teams; however, the Celtics are facing their own basketball mortality, and if the history of the 2010 NBA Playoffs has taught Celtics fans anything, it is that this group of Celtics will not exit without a fight for the ages.