RealGM

Does Defense Really Win Championships?
Posted by Neil Paine on August 27, 2010

Here are some quick logistic regressions I ran between offensive/defensive efficiency (as measured by my 1951-2010 estimation equation) and whether or not a team won a championship...

The first regression is between regular-season offensive/defensive rating (relative to the league average) and championships won since 1951, the first year for which I can estimate possessions. The logistic equation to predict championship probability from RS efficiencies was:

p(C) ~ 1 / (1 + EXP(4.7267572 - (0.3988116 * Offense) + (0.612137 * Defense)))

From this equation, we would expect an average team during the Regular Season (0.0 on offense & defense) to have a 0.9% chance of winning an NBA title. If you increase offense to the following levels while keeping defense average, you see this pattern:


Offense Defense p(C)
0.0 0.0 0.9%
1.0 0.0 1.3%
2.0 0.0 1.9%
3.0 0.0 2.8%
4.0 0.0 4.2%
5.0 0.0 6.1%
6.0 0.0 8.8%
7.0 0.0 12.6%
8.0 0.0 17.7%
9.0 0.0 24.3%
10.0 0.0 32.3%

Conversely, if you make the defense better while keeping the offense average, here are the expected championship probabilities:

Offense Defense p(C)
0.0 0.0 0.9%
0.0 -1.0 1.6%
0.0 -2.0 2.9%
0.0 -3.0 5.3%
0.0 -4.0 9.3%
0.0 -5.0 15.9%
0.0 -6.0 25.8%
0.0 -7.0 39.1%
0.0 -8.0 54.2%
0.0 -9.0 68.6%
0.0 -10.0 80.1%

As you can see, this result seems to bear out the old adage that "Defense Wins Championships"; for instance, to have the exact same title odds as a team with an average offense and a defense that was 5.0 pts/100 poss better than average, an average defensive team would have to score 7.7 more pts/100 poss than average!

However, we're taking into account all of NBA history here (well, except for 1950), and in case you forgot, there was this ridiculous defensive dynasty in the late '50s & 1960s that probably skews the findings heavily toward defense... Check out the Celtics' yearly offensive/defensive efficiency splits relative to the league average during their 11 championship seasons:

Year Team W L Champs Off Def
1957 Boston Celtics 44 28 1 0.27 -4.26
1958 Boston Celtics 49 23 0 0.35 -4.10
1959 Boston Celtics 52 20 1 0.69 -4.37
1960 Boston Celtics 59 16 1 1.41 -4.77
1961 Boston Celtics 57 22 1 -2.14 -6.37
1962 Boston Celtics 60 20 1 0.31 -6.85
1963 Boston Celtics 58 22 1 -1.75 -7.42
1964 Boston Celtics 59 21 1 -2.90 -9.27
1965 Boston Celtics 62 18 1 -1.11 -7.98
1966 Boston Celtics 54 26 1 -1.54 -5.57
1967 Boston Celtics 60 21 0 2.49 -4.14
1968 Boston Celtics 54 28 1 -0.48 -3.87
1969 Boston Celtics 48 34 1 -0.74 -5.52

(Note: Remember, positive is good for offenses, but negative is good for defenses.)

Boston's dominance during that stretch could possibly be inflating our sense of whether defensive teams are more likely to win because: A) Their defense was so historically outstanding in the Bill Russell era; and B) Their offense was so mediocre (they were below-average in 7 of the 13 years listed above!). To avoid the possibility of this skewing our sample, let's re-run the regression using only results since the 1976 ABA-NBA merger (and using the traditional possessions formula rather than the historical estimation):

p(C) ~ 1 / (1 + EXP(5.5573404 - (0.5306148 * Offense) + (0.6129486 * Defense)))

Once again, here are the tables for average defenses (left) and offenses (right):

Offense Defense p(C) Offense Defense p(C)
0.0 0.0 0.4% 0.0 0.0 0.4%
1.0 0.0 0.7% 0.0 -1.0 0.7%
2.0 0.0 1.1% 0.0 -2.0 1.3%
3.0 0.0 1.9% 0.0 -3.0 2.4%
4.0 0.0 3.1% 0.0 -4.0 4.3%
5.0 0.0 5.2% 0.0 -5.0 7.6%
6.0 0.0 8.5% 0.0 -6.0 13.2%
7.0 0.0 13.7% 0.0 -7.0 22.0%
8.0 0.0 21.2% 0.0 -8.0 34.2%
9.0 0.0 31.4% 0.0 -9.0 49.0%
10.0 0.0 43.8% 0.0 -10.0 63.9%

These findings still bear out the axiom of defense winning championships, but the split between offense & defense is much smaller than it had been when we included pre-merger seasons. Going back to our earlier example, to have the same p(C) as a team with an average offense and a -5.0 defense, an average defensive team would have to score only 5.8 more pts/100 poss than average if we use this equation.

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.

Great teams win championships. Doesn't matter which path you take, as long as you are scoring the ball more effectively than your opponent. Either by limiting them, scoring exceptionally well or preferably both.

There is almost always a team that is going to be GREAT at one and really good at the other, or even the rare team that is great at both, so the one dimensional teams get ousted.

NO-KG-AI wrote:Great teams win championships. Doesn't matter which path you take, as long as you are scoring the ball more effectively than your opponent. Either by limiting them, scoring exceptionally well or preferably both.

There is almost always a team that is going to be GREAT at one and really good at the other, or even the rare team that is great at both, so the one dimensional teams get ousted.

Yeah, this is why I always scoff when someone says the Spurs cheated to win in '07. The Suns were an elite offensive team, but average defensive team. That crap isn't going to get it done in the playoffs especially against an elite offensive and defensive team like the '07 Spurs.

you can't win anything without elite offense

stan1981 wrote:you can't win anything without elite offense

like the recent Pistons? Which championship team compares to the offense of the Suns btw?

Volcano wrote:

stan1981 wrote:you can't win anything without elite offense

like the recent Pistons? Which championship team compares to the offense of the Suns btw?

what, do you try to say that the Pistons with prime Billups and Rip were not an elite offesive team ??!
Have in mind that 'elite' does not mean the best. The Bobcats are considered an elite defensive team but their ceiling is the 8th seed

You don't need to be elite, but you definitely need to be able to still put the ball in the basket. Which is why teams like the 98 Cavs never won isht.

TAI8 wrote:Yeah, this is why I always scoff when someone says the Spurs cheated to win in '07. The Suns were an elite offensive team, but average defensive team. That crap isn't going to get it done in the playoffs especially against an elite offensive and defensive team like the '07 Spurs.

No one should look to put an asterisk on the Spurs - they were deserving champs.

However, it's utterly foolish to ever try to come up with a reason why one team couldn't possibly have beaten the other after a close series. In the world of sports playoffs, we live in a world of very small sample size, and any result that is close could have gone either way.

stan1981 wrote:

Volcano wrote:

stan1981 wrote:you can't win anything without elite offense

like the recent Pistons? Which championship team compares to the offense of the Suns btw?

what, do you try to say that the Pistons with prime Billups and Rip were not an elite offesive team ??!
Have in mind that 'elite' does not mean the best. The Bobcats are considered an elite defensive team but their ceiling is the 8th seed

Yeah, but the Pistons were ranked 18th offensively in 04.

Re: original post. This is an interesting analysis, I would like to see it more fleshed out though.

Questions I have:

Do defensive oriented teams do better in the regular season?
Are defensive oriented teams more likely to pull upsets in the post-season?

bballcool34 wrote:what, do you try to say that the Pistons with prime Billups and Rip were not an elite offesive team ??!
Have in mind that 'elite' does not mean the best. The Bobcats are considered an elite defensive team but their ceiling is the 8th seed

Yeah, but the Pistons were ranked 18th offensively in 04.[/quote]

Yeah, the Pistons offense was nothing like 'elite'. If you're not in the top 5 (or have a rating that's virtually tied with the top 5) you're not elite.

I also think it's strange to be shocked that Rip Hamilton's team wasn't elite, when I would never consider Rip to be an elite player. He's a solid player that made the all-star team because his team was so successful - which was largely due to defense, and he's not a defensive stud.

Just this past season, LA was 11th in Ortg, 4th in Drtg, in the regular season, and Boston was 15th in the regular season in Ortg, and 5th in Drtg. Boston especially and LA to a smaller extent visibly played better D in the playoffs, but I never thought either team got into a consistent offensive flow, and yet they were clearly the two teams playing the best ball, with Boston even outing an Orlando team that was playing top-tier offense and defense on the overwhelming strength of their own defense.

This isn't totally surprising IMO.

bottom line, no matter how much a team disrupt the opposition scoring, they still have to outscore them

stan1981 wrote:bottom line, no matter how much a team disrupt the opposition scoring, they still have to outscore them

lol, you do realize that you can outscore an opponent by only scoring, say, 70 points on 40% shooting (by any measure an awful offensive performance) if you hold the opponent to 65 points on 37% shooting or whatever.

What you said doesn't make a ton of sense. Technically, you only have to score 1 basket the entire game, if you hold the other team scoreless (the reductio ad absurdum for this argument). Again, its not too difficult to outscore a team even if you have a mediocre offense if your defense is disruptive enough to make their offense perform at a lower level than yours.

There's probably a lot of reasons for this, but a big one to me is great offensive players don't always play on great offensive teams, whereas almost every defensive stud anchored defensive stronghouses. Offensive players can just as often lead you to put defense only guys around them as it can to further supplant them with offense

So I'd still say great offensive players win championships. But great offensive players can help build great defensive teams as much as great offensive ones

mopper8 wrote:

stan1981 wrote:bottom line, no matter how much a team disrupt the opposition scoring, they still have to outscore them

lol, you do realize that you can outscore an opponent by only scoring, say, 70 points on 40% shooting (by any measure an awful offensive performance) if you hold the opponent to 65 points on 37% shooting or whatever.

What you said doesn't make a ton of sense. Technically, you only have to score 1 basket the entire game, if you hold the other team scoreless (the reductio ad absurdum for this argument). Again, its not too difficult to outscore a team even if you have a mediocre offense if your defense is disruptive enough to make their offense perform at a lower level than yours.

sure, it can happen on theory. In reality, teams that reach the finals have great offense and when two elite offensive teams meet, it's logical that the better defense will make the difference.
IMO, medicore offense means 15ppg and I doubt that any team in the history of NBA won a championship with even the 2nd option scoring less than 15

stan1981 wrote:sure, it can happen on theory. In reality, teams that reach the finals have great offense and when two elite offensive teams meet, it's logical that the better defense will make the difference.
IMO, medicore offense means 15ppg and I doubt that any team in the history of NBA won a championship with even the 2nd option scoring less than 15

You're completely clueless. Name all the teams in the NBA last year where the 2nd option scored less than 15 ppg.

stan1981 wrote:

mopper8 wrote:

stan1981 wrote:bottom line, no matter how much a team disrupt the opposition scoring, they still have to outscore them

lol, you do realize that you can outscore an opponent by only scoring, say, 70 points on 40% shooting (by any measure an awful offensive performance) if you hold the opponent to 65 points on 37% shooting or whatever.

What you said doesn't make a ton of sense. Technically, you only have to score 1 basket the entire game, if you hold the other team scoreless (the reductio ad absurdum for this argument). Again, its not too difficult to outscore a team even if you have a mediocre offense if your defense is disruptive enough to make their offense perform at a lower level than yours.

sure, it can happen on theory. In reality, teams that reach the finals have great offense and when two elite offensive teams meet, it's logical that the better defense will make the difference.
IMO, medicore offense means 15ppg and I doubt that any team in the history of NBA won a championship with even the 2nd option scoring less than 15

not sure about this but +/- Rockets 94 qualify. at least that's what I think.

Volcano wrote:

stan1981 wrote:sure, it can happen on theory. In reality, teams that reach the finals have great offense and when two elite offensive teams meet, it's logical that the better defense will make the difference.
IMO, medicore offense means 15ppg and I doubt that any team in the history of NBA won a championship with even the 2nd option scoring less than 15

You're completely clueless. Name all the teams in the NBA last year where the 2nd option scored less than 15 ppg.

I don't think it's so important but anyway - the Heat, the 76rs, the Pacers and the Timberwolves.
You got my point, if u have a real argument - say it

stan1981 wrote:sure, it can happen on theory. In reality, teams that reach the finals have great offense and when two elite offensive teams meet, it's logical that the better defense will make the difference.
IMO, medicore offense means 15ppg and I doubt that any team in the history of NBA won a championship with even the 2nd option scoring less than 15

Did you even bother to read the thread before responding? Here's the post immediately preceding yours:

I wrote:Just this past season, LA was 11th in Ortg, 4th in Drtg, in the regular season, and Boston was 15th in the regular season in Ortg, and 5th in Drtg. Boston especially and LA to a smaller extent visibly played better D in the playoffs, but I never thought either team got into a consistent offensive flow, and yet they were clearly the two teams playing the best ball, with Boston even outing an Orlando team that was playing top-tier offense and defense on the overwhelming strength of their own defense.

Both LA and Boston beat teams with far superior offenses as measured by points scored per 100 possessions. Boston beat the #2 offense (Atlanta) and the #4 offense (Orlando) because Boston D'd them up, not because the magically got better on offense.

LA beat the #1 rated offense in the league, Phoenix, even though they were only #11 in the league themselves in offense.

Oh, and you'll be hard pressed to argue that the #11 and #15 offenses in the league are somehow "elite"