The Spurs' Defense: Effects of Conference and Offense

[Editor's Note: This is the second in the series of posts we're doing examining the weakest of the Spurs' statistical measures, and deciding what conclusions can be reasonably drawn. (The first is here.) Fred Silva's recap of the second Jazz game will post later this morning. -jrw]

When looking at season-encompassing stats like defensive efficiency, it's important to realize that what's being measured includes a lot of outlier games, both favoring and hurting teams, and that the way the NBA schedule is established and what conference a team plays can also affect those numbers. The Spurs have dropped games by not playing the starters and have benefited from teams on the second night of a back to back; they also have to play Western playoffs teams more than, say, the Celtics do.

This is not an attempt to do away with defensive efficiency or any other number that doesn't help present the Spurs as elite. But this is a reminder that statistics need proper context to be reliable. With that in mind, let's look at those stats to see if, with some perspective, we can get a more valid read on the Spurs' defense.

The top 5 defenses according to defensive efficiency come from the East which is not surprising since a lot of the worst offensive teams also hail from that Conference. From that little factoid, it's easy to conclude that playing awful teams like the Wizards, Bobcats and Pistons a couple more times a year, can help skew the numbers in favor of the stronger Eastern Conference teams.

Knowing that, I decided to see how the best defensive team in the league, the Philadephia 76ers, fared against the West playoff teams. To my surprise, while their defensive efficiency did suffer a little, the Sixers were still good. They managed to keep the number of possessions low and had a defensive efficiency of 99.3, higher than their season average of 98.4 but still better than the Spurs' season average of 101.1.

So the Sixers defense is good regardless of the opponent. Why, then, aren't the Sixers an elite team?

In an e-mail exchange we had, Alamo sheds some light into it:

If you take a case like how the 76ers and the Spurs have each done against an opponent like the Magic, the 76ers defense might look as if it is better by allowing only an average of 87 points over three games vs. the Spurs 97 average over two games. On the other hand, the 76ers had to play their best defense over the entire game just to have a chance, as they lost 2 out of the 3, and Orlando was without Nelson and Richardson in the game the 76ers won (holding the Magic to 64 points); whereas the Spurs won both of their games. Is it just coincidence that the Spurs held the Magic to only 75 points in regulation time in the game they won in overtime, while giving up 111 points in a game they won by 11?

A team like the 76ers needs to play their best defense every single minute of every single game to have a chance to win. Of the 9 games against Western Conference playoff teams, the Sixers have only won 1 against the Lakers. Philadelphia has allowed their opponent to get more than 100 points 8 times this season and they've lost every single one of those games. Doug Collins and his guys know that in order to have any chance to win at all, they need to spend most of their energy focused on D.

The Spurs, on the other hand, are 13-7 against the West top 8 and have allowed their opponent to pass the 100 point mark a whopping 24 times this season but still managed to come up on top in 14 of those games. Most of those losses came early in the season, with only 2 in March.

Then there's outlier games. Instead of focusing in games where one team's defensive efficiency is hurt by a excessively high score caused by being short-handed (like the Portland game), I'll take a look at how good defensive teams feast on terrible offenses to improve their numbers. There have only been 20 games where a team allowed 70 points or less this season. Chicago has done that 7 times but those games have been either against awful teams (Charlotte, Washington, Toronto, Detroit, New Orleans), a good team that had by far their worst game of the season (Memphis losing by 40 points) and Orlando, who is the only team that has scored under 60 not once but twice this season. I don't want to take anything away from the amazing Bulls defense, but most of those teams have awful offenses. Philadelphia and Boston (two other elite defenses) have done that 3 times each against such offensive powerhouses as Orlando, Toronto, Sacramento and New Jersey.

What that means

The Spurs have such a potent offense that they don't have to play elite defense for every minute of every game to win. I've lost count of how many times the game was close, then the Spurs turn up the defensive heat and got a couple of stops in a row while continuing to score. With a sizable lead at hand the team just continues to execute well and manages the lead to get the win. That's the Spurs M.O. this season and it would worry me more if the defense wasn't so good in the clutch.

Teams like the Sixers, Celtics or Knicks need to play elite defense every second because their offense are nowhere near as good as the Spurs'. Those 3 teams currently have the 6th, 7th and 8th records in the weaker Eastern Conference and have a lower point differential than the Spurs. Only Boston would make the playoffs in the Western Conference with that record. And that's assuming that they'd even be capable of getting the same number of wins without feasting on the larger number of bottom dwellers that the East has.

As for simply looking at defensive efficiency numbers, we've seen some of the top defensive teams in the league "pad their stats" by crushing teams with terrible offenses, which begs the questions: is holding awful squads to low scoring numbers a good measure for a team's defensive aptitude? Wouldn't a stronger indicator of elite defensive ability be how well a team plays against great competition in close games where both teams were trying their best to score?

Conclusion

The Spurs are not an elite defensive team day-in day-out; that's partly because they don't need to be. Their offense is so good, that the team needs to apply itself on the defensive side for just enough time to get a good lead. When that doesn't happen and the games are close, the defense shines through, showing a glimpse that this team can be better than the numbers suggest.

We have "Defense wins championships" engraved in our basketball minds, but simply being a good defensive team means nothing, as the Sixers show. A better truism would be: Great teams win championships and the Spurs seem to be one, even if their defense doesn't measure up to what it was capable in prior championship seasons.

Defensive efficiency is a good stat, but needs to be put in context and the outliers considered, especially this season. In a normal, 82 games without back-to-back-to-backs Triple Lindys, the stats are a lot more reliable. But the problem is that this is not such a season. Having said that, the Spurs will need to play good defense consistently in the playoffs if they want another ring, but the personnel seems to be there for them to do so when the game requires it. The team depends more on its fantastic offense than its defense, but that doesn't mean the Spurs are not a good enough defensive team to contend.