Weekend is a two-part test for Celtics

In the NBA, championships are won in June, not in March. And yet, as the Celtics move toward a formal defense of their 17th world title, one cannot help but wonder if they have reached a crossroads.

Cleveland tonight.

Orlando on Sunday.

Which way will they go?

The Eastern Conference standings being what they are, we all understand the magnitude of tonight’s game against the Cavs. Home court advantage is probably at stake. The Celtics already trail Cleveland by two games in the loss column with 20 games to play, and a defeat tonight seemingly would give the Cavs a huge advantage in any tiebreaker implemented at the end of the season. Though the teams have a game remaining April 12 in Cleveland -- that’s Game 80 of the scheduled 82 -- Cleveland is a sterling 27-1 at home this year and beat the Celts, 98-83, in Boston’s only visit this season to Quicken Loans Arena.

With or without Kevin Garnett, the Celtics need to hold serve here.

Especially when one considers their recent road history against the Cavs.

For starters, the Celtics have not won at Cleveland in six tries during the Garnett era. In the last four trips there -- three of them in last year’s Eastern Conference semifinal series -- the Celtics have lost by scores of 108-84, 88-77, 74-69, as well as the aforementioned 98-83. Add up the numbers and what you get is the scoring average of a dreadful 78.3 points per game in those affairs, the kind of Q rating that qualifies as an F on most any scale.

Get the picture?

While Cleveland has been unable to win at the TD Banknorth Garden over the same stretch of time -- the Cavs are 0-7 in Boston in regular- and postseason since the beginning of last season -- the pressure is actually on the home team tonight. Should Celtics lose to the Cavs tonight -- and presuming Cleveland also wins at home April 12 -- Boston will need to make up four games in the remaining 18 to earn home court advantage throughout the Eastern Conference playoffs.

If you think that is going to happen, you have as warped a sense of self as Lucky, the deposed leprechaun.

In the short term, the problem is that the Celtics will play this game without Garnett, the reigning Defensive Player of the Year who once again was starting to look like the most valuable defensive force in the league. Particularly against a Cleveland team that has held opponents to a league-low 90.3 points per game, Garnett will be missed. In the nine games Garnett has missed this season, the Celtics have allowed precisely 99.2 points per game; in the 53 games Garnett has played, the Celtics have allowed an average of 91.5.

And so, if you’re looking for a way to measure what Garnett brings to the table defensively on a nightly basis, it translates into about 7.7 points per contest. And oh, by the way, the Celtics’ average margin of victory this year is 9.1. Think about all of this the next time someone suggests that Garnett does not "take over" games in crunch time.

As for Sunday’s home game against Orlando, we all would be advised to remember the Magic. At the moment, in the loss column, the Celtics (14 defeats) are as close to Orlando (16) as they are to Cleveland (12). Should the Celtics suffer defeats to both the Cavaliers and Magic this weekend, there is the chance the Celtics will finish third in the Eastern Conference. That means Boston could lose home court advantage as early as the second round, a daunting prospect no matter how much the Celtics improved on the road throughout the course of last postseason.

Admittedly, a great deal has changed since last week, let alone last spring. The Celtics added Stephon Marbury and Mikki Moore, and the Cavs just picked up Joe Smith. Orlando hoped to mitigate the loss of point guard Jameer Nelson by picking up Rafer Alston from the enigmatic Houston Rockets. On some level, each of the three elite teams in the Eastern Conference have been undergoing some sort of molecular restructuring, all with the singular purpose of defeating the other two in May.

Last year, for what it’s worth, the Celtics picked up their play considerably down the stretch, winning 16 of their final 20 games and 11 of their final 12 after going 50-12 in their first 62. At the moment, this club is two games off that pace at 48-14. As it turns out, those two games are currently the difference with regard to potential home court advantage against a hungry and improved Cavaliers team whom the Celtics are almost certain to face in the Eastern Conference playoffs.

Two games.

And so as the Celtics prepare for meetings with the Cavs and Magic this weekend, maybe it is worth remembering that a mere two games can make all the difference in the world.