It's time to retire the outdated NBA axiom that defense wins championships.
It's an oversimplification, it's misleading and it was never technically true in the first place.
We'll dive deeper into the "why" momentarily, but first let's propose a refined version of that old cliche that better reflects what the data reveals. It could go something like: "Championships aren't won on defense alone. You need balance, effective offense and, ultimately, the ability to get the job done at a nearly elite level on both ends."
That doesn't quite have the same ring to it, huh?
At any rate, here comes some bad news for teams in this season's NBA playoff crop that have plenty of stopping power but little offensive punch. As we'll see, championship squads are almost always the ones who can get buckets and stops in equal measure.
Neil Paine of Basketball Prospectus (via Basketball-Reference.com) looked at 50 years of NBA data to determine whether offense or defense was the more important ingredient in a championship recipe:
These findings still bear out the axiom of defense winning championships, but the split between offense and defense is much smaller than it had been when we included pre-merger seasons. ...
... However, the continued prominence of defense even when we drop the heavily D-oriented Celtics dynasty from the sample does suggest that, all things being equal, teams should prioritize excellence at that end of the court if they want to win a championship.
So, if we have to choose between great offense or great defense, Paine's research suggests defense is the way to go. But we shouldn't jump from that statement to the ironclad conclusion that defense can win championships on its own.
That's not what Paine is saying at all.
And it's not as if NBA teams can simply choose to be great at either defense or offense. They do their best (tanking teams excluded) to be good at both. Usually, excellence on defense is a result of some combination of smart scheming and the right personnel. In many cases, teams without elite scoring talent have no choice but to focus on defense.
Andres Alvarez of The Wages of Wins Journal broke down the offensive and defensive ratings of every team to make the NBA Finals since the introduction of the three-point line in 1979-80.
Represented below is the section of his findings that details the more recent Finals participants, from the 1999-00 season until last year. (Note: Alvarez published his study before the 2013 NBA Finals; I added the data from the Miami Heat and San Antonio Spurs from that season.)
|Champ||ORtg (Rank)||DRtg (Rank)||Runner-Up||ORtg (Rank)||DRtg (Rank)|
|2012-13||Heat||112.3 (2)||103.7 (9)||Spurs||108.3 (7)||101.6 (3)|
|2011-12||Heat||106.6 (8)||100.2 (4)||Thunder||109.8 (2)||103.2 (11)|
|2010-11||Mavericks||109.7 (8)||105 (8)||Heat||111.7 (3)||103.5 (5)|
|2009-10||Lakers||108.8 (11)||103.7 (4)||Celtics||107.7 (15)||103.8 (5)|
|2008-09||Lakers||112.8 (3)||104.7 (6)||Magic||109.2 (11)||101.9 (1)|
|2007-08||Celtics||110.2 (10)||98.9 (1)||Lakers||113 (3)||105.5 (5)|
|2006-07||Spurs||109.2 (5)||99.9 (2)||Cavaliers||105.5 (18)||101.3 (4)|
|2005-06||Heat||108.7 (7)||104.5 (9)||Mavericks||111.8 (1)||105 (11)|
|2004-05||Spurs||107.5 (8)||98.8 (1)||Pistons||105.6 (17)||101.2 (3)|
|2003-04||Pistons||102 (18)||95.4 (2)||Lakers||105.5 (6)||101.3 (8)|
|2002-03||Spurs||105.6 (7)||99.7 (3)||Nets||103.8 (18)||98.1 (1)|
|2001-02||Lakers||109.4 (2)||92.1 (6)||Nets||104 (17)||99.5 (1)|
|2000-01||Lakers||108.4 (2)||104.8 (21)||76ers||103.6 (13)||98.9 (5)|
|1999-00||Lakers||107.3 (5)||98.2 (1)||Pacers||108.5 (1)||103.6 (13)|
Wages of Wins
In looking at those regular-season numbers, we can clearly see a good defensive rating is strongly correlated with making the Finals and, ultimately, winning a championship. On average, Finals participants since 2000 have sported the fifth-ranked defense.
There are outliers, with the 2001-02 Los Angeles Lakers and their No. 21 defensive rating standing out in particular. But with very few exceptions, a top-10 defense is a prerequisite to making the Finals.
That's not news, and nobody's arguing against the importance of defense in the pursuit of titles. But we also have to take into account the fact that the average ranking of those teams' offensive ratings was also right around No. 5.
In other words, offense and defense are important in almost exactly equal measure.
That brings us to Alvarez's conclusion, which takes into account the teams represented in the chart above but also incorporates data from the 1980s and 1990s:
The key to winning in the NBA is point differential. ... As such, a team needs to be good at offense, defense or both.
And in fact, that's what we see. 26 out of our 33 title teams were top 10 in both defense AND offense (with the 1996 Chicago Bulls amazingly being number one in both). It's a bit further down for runner-ups. Only 15 out of 33 were top 10 in both offense in defense. However, across all of our teams, every single one of them was top 10 in either offense or defense. (Which is how teams like the 2004 Pistons and 2001 Lakers still won despite being poor at offense and defense, respectively).
How surprising is that, really?
It turns out teams that are comprehensively dominant—as reflected by a net rating figure that subtracts the number of points they allow from the number of points they score per 100 possessions—tend to wind up in the Finals.
You don't say.
So, what's that conclusion mean for some of our defense-only championship hopefuls this year? Now that we know it takes balance to win a ring, you can probably guess.
They're viewed by many (as they were last year) as a tough team with whom no opponent would relish a postseason matchup. Chicago's defense is elite, and coaches around the league aren't shy about praising it:
Brad Stevens just said that this Chicago defense is "as good of a defense as I've ever coached against."— Boston Celtics (@celtics) April 1, 2014
But the Bulls rank just 28th in offensive rating. No team in the modern era has even sniffed the Finals with an offense that bad, let alone come close to a championship. Chicago's net rating is positive, at plus-1.9 points per 100 possessions, but its gross statistical imbalance means there's no realistic scenario in which it wins a title.
The Indiana Pacers are a more complicated story, but one, unfortunately for Indy fans, that features a similar ending.
Indiana's overall season numbers are somewhat misleading because the team has fallen off a cliff over the past couple of months. Even if we afford the Pacers the benefit of including their early-season excellence, we find they also fall short of profiling as a championship team.
Indy's offensive rating checks in at No. 22 in the league, which means its No. 1 defensive rating will almost certainly go to waste. The Pacers can look to that 2001 Lakers team as a sign of hope, as that group managed to win a ring with the No. 21 defense and No. 2 offense.
Unfortunately, we can't look at Indiana's overall numbers as indicators of its future performance. The Pacers are a different team than they were a few months ago, and their statistical profile is far worse.
This Pacers offense is a dumpster fire.— Haralabos Voulgaris (@haralabob) April 6, 2014
Since the All-Star break, Indiana's offensive rating has been the league's second-worst, and its defense has slipped six spots to No. 7. There's no precedent for a team with those ratings winning a ring.
The Golden State Warriors are an interesting case. They currently have a defense that's tied for third in the NBA and an offensive rating that falls narrowly outside the top 10.
Of this year's playoff teams who could fairly be termed defense-first outfits, they're the one that fits the mold of a potential championship team most closely. Because of their relatively balanced attack, the Dubs might not even properly fit into the category occupied by teams like Chicago and Indiana.
At any rate, the Warriors have the best historically based chance to win a ring on the strength of their defense.
For what it's worth, the San Antonio Spurs, Los Angeles Clippers and Oklahoma City Thunder all have offensive and defensive ratings that are both in the top 10. And the Miami Heat and Houston Rockets miss that distinction by fractions of a point in their No. 11 and No. 12 defensive ratings, respectively.
Those are the types of balanced teams most likely to win a title, not one-dimensional squads like the Bulls or Pacers.
The Simplest Explanation
A good defense is generally important in winning a championship, but we have no evidence to suggest a team could win a ring on the strength of its stopping power alone.
Based on Paine's work, many have concluded that a good defense is marginally more important than a good offense, but Alvarez's research suggests the difference is practically negligible. What matters is effective, top-10 ratings on both ends of the floor.
So, defense does win championships, but only if it's paired with a good offense. How's that for a revelation?
Advanced stats courtesy of NBA.com/Stats unless otherwise noted.