The Spurs' Defense Has Played Better Against Tougher Competition This Year

[Editor's Note: This is the third 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, the second is here. The number for this story are current through Monday's game against the Jazz. -jrw]

In the last two posts, we've discussed the rest that the Spurs are giving their stars while other contenders are using them for extended minutes and the way the Spurs excellent offense allows the team to often coast to wins while the disparity in the quality of conferences inflates the defensive numbers of Eastern teams.

None of that means we shouldn't be worried about the defense, but it suggests that looking at the numbers without context makes the Spurs' defense seem less effective than it really is. For this post I'll focus on a stat that is often overlooked but could be one of the better predictors for team success. I'll also take a look at how the Spurs defense fairs against the West playoff teams.

Margin of victory might be a better indicator of a true contender than defensive rating

Over the last ten seasons, the lowest a champion has been in terms of defensive rating was 10th in the league (Miami heat, 2006 season) and the average defensive rating position of all champions is around 4th. Meanwhile, the average position in terms of offensive rating is around 8, with only 3 champions being in the top five and the 2004 Detroit Pistons actually finishing 18th in the league. That does provide some credence to the "defense wins championships" truism, but a better way of telling when a team is good might be margin of victory. While defensive rating numbers see fluctuation from champion champion, every team that has won a title in the last ten years has been in the top ten in the league in point differential with three teams finishing 1st, three teams finishing second and only two teams finishing outside of the top five. The Spurs rank 2nd in offensive rating, 12th in defensive rating and 4th in margin of victory; behind Chicago, Miami and Oklahoma City

There are a few teams above the Spurs in defensive rating that are not going to win the championship any time soon, most of which come from the Eastern Conference. The Western conference teams that are better defensively than the Spurs are the Mavericks the Grizzlies and the Thunder. Of those teams, only OKC has a better margin of victory than the Spurs, with the Grizzlies ranking 14th and the Mavs 16th in the league.

I would love to see improvement in the Spurs' defensive numbers, but there are other stats that suggest the Spurs are contender good. Most of the teams that advance deep in the playoffs have good to excellent margin of victory numbers.

The Spurs defense remains consistent regardless of rival and even if the defense is not as good as other team's, the Spurs still get better results

We've touched on this in the last post, but it's worth rehashing here. Against Western playoff teams the Spurs have pretty much the same defensive rating as their season average (103.5 for the season, 103.2 against Western playoffs teams). They allow those teams .343 from beyond the arc and .448 field goal percentage, marks that are slightly better than their season averages of .361 and .454. Of the 20 games the Spurs have played against the West playoff teams, 12 have been against Oklahoma, Denver and Houston, teams that are in the top ten in offensive rating.

The Thunder have won 14 of 21 games against Western playoff teams but they allow better percentages than their season averages. The same goes for the Heat, who have only won 5 out of 10 against those teams, the Bulls (4-4) and the Celtics (3-7). The Knicks allow a better overall field goal percentage but a lower 3-point percentage and the Sixers are the only elite defense that does slightly better against the West top 8.

That means that even while the numbers put the Spurs' defensive rating below than that of the elite defensive teams, the Spurs do well against their likely playoff foes, and actually show relative improvement (albeit marginal) in their defense in such games.

Conclusions from the series of posts

The Spurs are different than other contenders in that they don't play their stars as much as the rest of the contenders to, and one of their best players missed much of the season with injury. Those two facts, plus Pop's usual rotation experiments, make it hard to draw any definitive conclusions as to team's true ceiling on defense. When the dust settles and Pop finds the rotations he is going to stick with in the playoffs, the Spurs could very well prove to be an elite defensive team

While stats are a very important tool to measure a team efficiency on both sides of the ball, I've argued for context -- especially in this compressed season. The imbalance between the level of play in conferences needs to be accounted for, especially since this season Western teams play many Eastern teams only once. Since there are more bad teams in the East, the best teams in that conference get to exploit those match-ups to improve their numbers. Add to all the above the fact that the Spurs often choose to rest their stars, and you have a recipe that can create some statistical anomalies that make it very difficult to nail down the team's real defensive aptitude.

The Spurs team as a whole is ranked with the rest of the league's elite in margin of victory, and again that stat has been a more consistent indicator than defensive and offensive rating in predicting overall team success. Several of the teams that are ahead of the Spurs in defensive rating don't figure to be real contenders, and the fact that the Spurs' defense is as good or better against the teams they'll have to face in the playoffs is reason for optimism.

Does this mean that the Spurs are a near perfect team with no weaknesses? Not at all. I still worry about the lapses in defense within games and about whether the offense is going to be able to maintain its elite level in the playoffs (with these fears being burgeoned by the fiasco of the recent Lakers game). But these posts were always more about dispelling the notion that the Spurs weren't for real because of their overall defensive stats, than they were any attempt to prove the Spurs were the best team in the league and secretly a defensive powerhouse.

The final thought I'd like to leave you with is this: even if they are not the traditional championship team, the Spurs are definitely legitimate contenders.