How do you measure a team's defense?

[Illuminatos]

Ok so my friend is arguing with me that the Knicks are a terrible defensive team while I'm telling him they're not really that bad since they were ranked 5th in defense this year.

http://espn.go.com/nba/hollinger/teamst ... order/true

So now he tells me the most important stat is point allowed per game and the Knicks are 11th in that.

http://espn.go.com/nba/statistics/team/ ... tsOpponent

So can someone explain which is a better indication of how good a team's defense is because no matter what I say he just brushes it off and says the Knicks played no D.

[Wone]

defensive rating is the best no doubt. points per game allowed is useless since it doesn't distinguish from pace so some team's points per game allowed may be higher than others despite being a better defensive team due to pace.

[Wannabe MEP]

5th best defensive team last year is accurate. Massive shift from 2010-2011 to 2011-2012: Defense got a ton better, offense got a ton worse. Why? TYSON CHANDLER. D'Antoni's system is built on paint spacing and quickness. When you play Amare at the five with a stretch-4, you leave the paint wide open and Amare can out-quick everyone else's 5. But Amare sucks as the defensive 5.

If you insert T. Chandler at the five, Amare moves to the four:

-Spacing advantage? Gone.
-Amare's quickness advantage? Gone.
-Defensive disadvantage? Gone.

[An Unbiased Fan]

TS% OPP is the best.

I have recently come to this conclusion as I survey past seasons. For example, in 2001 the Phoenix Suns were #1 in DRtg at an eye-popping 98.0, and the Spurs were #2 at 98.0

I can tell you that no one in their right mind thought the Suns were a better defensive team back in 2001.

Now let's look at their TS% OPP:

Suns - 51.2% TS OPP

Spurs - 48.3% TS OPP

League Average - 51.8% TS OPP
^
So what we see is that the 2001 Spurs were -3.5% TS tougher than the average team, while the Suns were barely -0.6% better than average. That's astounding, and rings more true based on watching the 2001 season.

I've been re-thinking ORtg/DRtg as the standard for offensive/defensive efficiency. I'm starting to see that the methodology is flawed. The "possession" stat doesn't mix well at all, and warps the data.

[mopper8]

But TS% does not include turnovers, which matter defensively. Ostensibly, the drawback to "gambling" on turnovers is that you leave the rest of the defense open to a high % shot, but that's already built in to the TS% calculation. Which means, if two teams have identical Opp TS%, but one creates more turnovers than the other, the team creating more turnovers is clearly the superior defense. But you'd miss that by focusing on TS%.

[mopper8]

I also don't think the 2001 Suns being so good defensively is that shocking. That wasn't the Nash/D'Antoni Suns. Their top 3 in minutes played were Kidd (excellent defender at the time), Marion (athletic versatile defender), and Cliff Robinson (tall, athletic versatile defender). They were coached by Scott Skiles, who's coached a number of good defenses despite wide variations in talent, e.g. 05 Bulls (2nd in the league in Drtg), 10 Bucks (2nd in Drtg)

Its not like those Suns were a bad team either...they won 51 games. While being 22nd in Ortg. 22nd in eFG% as well.

[mopper8]

Also, TS% does not consider defensive rebounds, which quite clearly have a large impact on defense.

[WhatRickyThinks]

Opp TS is hinged on free throw percentage which has nothing to do with defense. eFG would be better, no?

[mopper8]

Opp TS is hinged on free throw percentage which has nothing to do with defense. eFG would be better, no?

FT/FGA is going to have a much bigger impact on Opp TS than Opp FT%

[WhatRickyThinks]

Chauncey Billups and Shaquille O'Neal tend to disprove that, no?