Three title contenders already improving their flaws

With 64 games settled, the NBA season already is about 5 percent complete.

History tells us that the time to really start evaluating teams is at the 20-game (six-week) mark. But that doesn't mean that we can't draw some conclusions after nine days.

For now, we'll focus on three teams that are serious contenders for the championship: the Lakers, Celtics and Heat. This list may expand or contract as the season goes on, but it's too early to include teams like the 3-1 Mavs (who rank fourth in point differential per 100 possessions), the 5-0 Hawks (fifth) or the 4-0 Hornets (sixth). It's also too early to eliminate the 2-1 Magic, even though they got spanked by the Heat last Friday.

But, we need to wait before looking deeper into Orlando's numbers. It has played just three games, and the average margin of victory in its last three games is 32.3 points. Good luck concluding anything from that sample.

Instead, here are trends to watch in L.A., Boston, and Miami.

So far, the league is scoring 102.5 points per 100 possessions -- down from last season's mark of 104.9. A slow offensive start league-wide is normal and efficiency will improve, but the 102.5 mark is also down slightly from this point a year ago (103.0).

Still, there are a few teams that are already scoring more efficiently than they did last season. At the top of the list are the Lakers, who are the No. 1 (and most improved) offensive team in the league, scoring 114 points per 100 possessions.

Now, it may seem natural that the Lakers, with all the talent that they have, would be a top offensive team. But last season, for various reasons, the Lakers' offense was pretty mediocre, ranking 11th in the league and scoring just a point more per 100 possessions than the league average.

As noteworthy as it was that they weren't great last season (they ranked third the two previous seasons), it is more noteworthy that they look to be much improved this year. And that improvement is across the board: they're shooting better, getting more offensive boards, turning the ball over less and getting to the line more.

If the Lakers can combine a more potent offense with a defense that has improved each of the last four seasons, they could be a more dominant regular-season team than they were last season, when they had 57 wins, won the West and won the title.

But it must be noted that the five teams the Lakers have played (Houston, Phoenix, Golden State, Memphis and Sacramento) all rank in the bottom half of the league defensively. Four of those five are in the bottom 10, and three are in the bottom five. Their first real test will come Sunday against the Blazers, who rank eighth defensively.

No team's rebounding numbers regressed more than the Celtics last season. And Doc Rivers will be the first to tell you that it was rebounding that was his team's downfall in the Finals. Just check the 23 offensive rebounds they gave up to the Lakers in Game 7.

Rivers is happy to concede defensive rebounds to his opponent -- he'd rather his team get back and stop transition than go for offensive boards -- but the Celtics were just an average defensive rebounding team last season, ranking 13th by grabbing 73.8 percent of available defensive boards.

So far this season, the Celtics rank fifth at 76 percent. They're a great defensive team overall, but with all the shots that their opponents miss, their ability to finish off possessions with a rebound is critical.

With an improvement on the offensive glass as well, Boston is the fourth most-improved rebounding team overall, behind Golden State, New Jersey and Orlando.

The most improved defense is in Miami, where the Heat are holding teams to a ridiculously low 87.9 points per 100 possessions.

Three seasons ago, the Celtics had the best defense of the last 20 seasons, allowing 8.6 points per 100 possessions fewer than the league average. Miami isn't going to hold its opponents to 14.6 points fewer than the league average all season, but that five-game mark is impressive. In 2007-08, the Celtics had just three five-game stretches where they held their opponents under 88 points per 100 possessions.

Boston's best defensive five-game stretch came right after Thanksgiving that season, when the Celtics held five opponents to 86.1 points per 100 possessions. They were actually more dominant to start last season, when they were holding their opponents to 85.2 points per 100 possessions after five games and 85.4 after six.

The Heat would have to have another dominant defensive performance in New Orleans on Friday to match that six-game start, but for them to come close in their first five games together (with two of the games against strong offensive teams like Boston and Orlando) is pretty scary.

John Schuhmann is a staff writer for NBA.com. You can e-mail him here and follow him on twitter.

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