Now that we are three weeks into the NBA's 2009-10 campaign and most teams have completed 10 games, we're starting to see the numbers settle down and early-season flukes fade away. There is one notable exception, however: the leaderboard in team defense. While the Boston Celtics posting the league's best Defensive Rating is no surprise, some unlikely contenders have joined them in stifling the opposition.
Besides the Celtics, through Wednesday just two other teams from last year's top 10 defensive teams on a per-possession basis were repeating the feat so far this year (the Charlotte Bobcats and L.A. Lakers). While sample size surely has something to do with this, the NBA's elite offenses have been much more consistent--seven of last year's top 10 offenses are still in the top 10 this season.
To see if any conclusions can be drawn, let's take a team-by-team look at the changes to the top 10 on defense.
2. Portland Trail Blazers (100.0 Defensive Rating; 12th last year)
That the Blazers would move into the top 10, having ranked not far outside a year ago with a growing roster, was not unexpected. That Portland would be in the running for the league's best defense very much is a surprise. The Blazers have done it despite losing their best perimeter defender (Nicolas Batum) to shoulder surgery and moving to a small backcourt of Steve Blake and Andre Miller. In part, their recent success is attributable to playing just one strong offense (San Antonio) during a six-game winning streak. Over the course of the season, however, Portland has faced a slate of opposing offenses not much worse than league average. The Blazers are holding opponents to the league's lowest effective field-goal percentage on the strength of limiting them to 43.7 percent shooting on two-point shots. A lot of credit has to go to Greg Oden's development as a paint protector, but additionally Nate McMillan (and leader Brandon Roy) emphasized defense in training camp and that focus appears to be paying off.
3. Chicago Bulls (100.2 Defensive Rating; 18th last year)
For Chicago, it is back to the future as the Bulls embrace their Scott Skiles-era roots as a stout defensive squad that struggles to put the ball in the basket. While remaining ninth in the league in eFG% surrendered, Chicago has improved in each of the other Four Factors. The most noteworthy makeover is in terms of putting opponents on the free throw line; the Bulls rank second this year in opponent free throws made per field-goal attempt. It's mostly been a team effort, but Chicago has benefited from foul machine Aaron Gray (2.4 fpg in 12.8 mpg a year ago) being sidelined.
4. Miami Heat (101.0 Defensive Rating; 13th last year)
We touched on the Heat's success defending the three last week, noting that it is unlikely to continue. Lo and behold, opponents are already up over 30 percent from beyond the arc and Miami has lost three of its last four games.
5. Oklahoma City Thunder (101.5 Defensive Rating; 21st last year)
With the Heat's slide, it is now Oklahoma City that has seen opponents shoot the lowest percentage from downtown this season (28.3 percent). Even with average three-point shooting, however, the Thunder would be near the league's top 10 in defense, which represents a pretty remarkable improvement for a team that tried to outscore opponents at times last season. Give a lot of the credit to two imports from Chicago. Former long-time Bulls assistant Ron Adams joined Scott Brooks' staff midway through last year and helped improve the defensive schemes. Around the same time, Oklahoma City dealt for swingman Thabo Sefolosha, who has begun to make good on his potential as a stopper for the Thunder.
6. Dallas Mavericks (101.9 Defensive Rating; 16th last year)
The Mavericks have reversed last year's defensive slide by making incremental improvements across the board. Shawn Marion's athleticism has helped, while rookie Rodrigue Beaubois gives Dallas a better matchup for the league's quicker point guards.
7. Milwaukee Bucks (102.1 Defensive Rating; 15th last year)
Skiles' current charges have continued the improvement they made a year ago, going from the league's worst defense in 2007-08 to a top-10 squad within two years. The key this season has been Milwaukee's boardwork; the Bucks lead the NBA in defensive rebound percentage. Ersan Ilyasova (26.4 percent of available defensive rebounds) has been pounding the glass off the bench, and Brandon Jennings (14.3 percent) is very good for a point guard.
9. Indiana Pacers (102.4 Defensive Rating; 19th last year)
The Pacers set out to upgrade their defense incrementally last summer, and the additions of Dahntay Jones and Earl Watson have paid dividends so far. Indiana has gotten an even bigger lift from the development of second-year center Roy Hibbert, who is blocking 6.4 percent of opponents' two-point attempts. Among starters, only Oden (7.5 percent) has a better block rate. Fittingly, the Blazers and Pacers are first and second in the league in defensive field-goal percentage.
1. Orlando Magic (104.9 Defensive Rating, 12th)
The league's best defensive team a year ago has struggled at times this season. Orlando has been playing some makeshift lineups with Rashard Lewis suspended until Monday and a variety of players hobbled. Still, the poor start has been a cause for alarm for the Magic, with Stan Van Gundy criticizing the defensive efforts of Jameer Nelson and reigning Defensive Player of the Year Dwight Howard. Before Nelson was sidelined by a torn meniscus, Orlando was 4.6 points worse per 100 possessions on defense with him on the floor. Oddly, while the sample size is small, no other full-time starter has been a net minus defensively. As for Howard, his blocked-shot rate is down from last year's 5.9 percent to 4.4 percent, more in line with his career numbers. Equally troubling is that Howard's foul rate is up from 4.2 percent of possessions last year to 6.0 percent this season. Howard is too good not to improve on that, which will help the Magic's defense as a whole.
3. Cleveland Cavaliers (103.4 Defensive Rating, 11th)
In fairness, the Cavaliers are comfortably better than the league average (107.3) on defense, and missed out on the top 10 in part because of a logjam late in the rankings. Still, it is interesting that so much more attention has been paid to Cleveland slumping on offense when the defense has also tumbled. The two may be related, however. According to 82games.com, the Cavaliers have been significantly worse defensively with LeBron James at power forward in small lineups Mike Brown has used to counteract the lack of shooting from his frontcourt. Cleveland has defended much, much better with Anderson Varejao on the floor.
4. Houston Rockets (106.5 Defensive Rating, 15th)
So far this season, the Rockets have been better on offense than on defense. Houston's undersized posts have been effective taking on more possessions, but have struggled to replace Yao Ming's shot-blocking presence in the middle. The Rockets have also been less effective on the defensive glass, though their stylistic metamorphosis also includes forcing more turnovers this season. Still, it looks like Houston will drop out of the top 10 in Defensive Rating for the first time since 2002-03, Yao's rookie season. This is probably not a coincidence.
6. San Antonio Spurs (111.5 Defensive Rating, 23rd)
The NBA's defensive dynasty has ranked in the top 10 in defense every year in the Tim Duncan era. In fact, aside from the injury-plagued season that landed the Duncan pick, the Spurs have been in the top 10 every year through the David Robinson era--19 times in 20 seasons. Given that San Antonio started slowly at the defensive end a year ago, it's far too early to declare that streak in jeopardy. The Spurs' complete and total lack of shot blocking is a tad disconcerting, however. With Duncan limited, San Antonio is 29th in the league in blocked shots. (On the other hand, ranking 30th hasn't stopped the Bucks from putting together a quality defense.)
8. Denver Nuggets (107.5 Defensive Rating; 17th)
The Nuggets have been more effective than in 2008-09 in the early going, but they've done it with far less balance, surging on offense and slipping on defense. The departure of Jones might have something to do with that. Denver's defense has been built largely on turnovers that have not been as frequent this season. The Nuggets' steal rate remains strong, so they may have had some bad fortune in terms of "unforced" turnovers.
9. New Orleans Hornets (113.9 Defensive Rating, 27th)
For all their other shortcomings, it has been dismal defense that has done in the Hornets. Swapping out Tyson Chandler for Emeka Okafor has been a disaster so far, though the optimistic position is that Okafor has as yet been unable to build chemistry with his teammates because he missed all of training camp. By the way, does it concern anyone else that David West's defensive rebound percentage is equal to Brandon Jennings'?
10. Atlanta Hawks (106.5 Defensive Rating, 14th)
Like the Nuggets, the Hawks will happily exchange a slight decline on defense for the massive leap forward they have taken in terms of scoring efficiently.
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Kevin Pelton is an author of Basketball Prospectus.
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