Why don't advanced stats like Bradley's defense?

[Rondo9]

He has a negative Defensive Boxscore Plus Minus.  His DRPM is negative also, and ranked quite low leaguewide.  He has 2.6 Defensive Win Shares on the season, which is fine, but not close to top 20.  His defensive rating is 106, which is not horrible, but not particularly great either.  His steal percentage of 2.2 is fine but far from exceptional.

Part of it is that these metrics are awful measures of defensive ability. Another part is that his defense is somewhat overrated.

You are right about #1 but the debate comes from both Lillard and McCollum stating that they believe he is the best.  And they would know much better than anyone on this blog.

The fact that Lillard and McCollum doesn't like having someone in their face when they dribble the ball doesn't necessarily make them an overall impact defender.

What about guys like Steph Curry who praised Bradley's defense?

[Dino Pitino]

http://forums.celticsblog.com/index.php?topic=83700.0

[PhoSita]

The fact that Lillard and McCollum doesn't like having someone in their face when they dribble the ball doesn't necessarily make them an overall impact defender.

Right, I tend to think at least part of his rep is that subjectively it's really annoying to be the primary ballhandler when there's a guy relentlessly hounding you every second.

I'm sure that translates to better defensive outcomes, but it might not have quite the impact that players feel that it has, since Bradley doesn't actually generate that many steals (at least, it doesn't show up in the box score).

[PhoSita]

Also note that DBPM seems heavily skewed toward big guys - like, insanely so.

http://www.basketball-reference.com/leaders/dbpm_top_10.html

And we have two guys in the top 20 - Amir and Sully. KO's is quite good too.

It seems possible to me that DBPM somehow assigns good perimeter defense to the big guys playing with those defenders. Like, perhaps a primary effect of good perimeter defense is that teams take more difficult interior shots?

I'd have to dig into the mechanics of it though to say for sure.

I suspect that credit for defensive rebounding and opponent shooting inside gets assigned to big men.  So that would be consistent with what you're saying.  Big men who position themselves well in the paint and box out properly will reap the rewards in the stats that perhaps should go to the perimeter defenders that funnel offensive players into interior help in the first place.

[wayupnorth]

Very disappointing to see how many Boston fans here do not see the HUGE impact Bradley has on our defense.

He DOES deserve to be first team all-defense.

He IS one of the top 3 perimeter defenders in the league, and the only guys who are better, are only better because of their size. They do not have the foot speed or lateral quickness Bradley has.

This thread just confirms how incredibly underrated Avery is around here.

Very interesting question in the OP, but again, I cannot believe the lack of respect Avery's defense gets around here.

[PhoSita]

http://forums.celticsblog.com/index.php?topic=83700.0

Reading that article about what C.J. said, it occurs to me that nobody gives Ricky Rubio enough credit for how good he's become defensively.

[loco_91]

Does anyone actually know how these stats are calculated? My impression is that they leave a lot to be desired. Defense is just tough to quantify. But from the eye test its pretty obvious that AB is a great defender, idk about best in the league though.

[KG Living Legend]

Very disappointing to see how many Boston fans here do not see the HUGE impact Bradley has on our defense.

He DOES deserve to be first team all-defense.

He IS one of the top 3 perimeter defenders in the league, and the only guys who are better, are only better because of their size. They do not have the foot speed or lateral quickness Bradley has.

This thread just confirms how incredibly underrated Avery is around here.

Very interesting question in the OP, but again, I cannot believe the lack of respect Avery's defense gets around here.

 I respect his defense that's for sure. It's not quite where it used to be when he burst into the scene, but still excellent.

 One advance stat had him at #352 in the league. That stat should be disregarded from now on.

[Roy H.]

Defensive stats are largely bunk. They don't adequately take into account things like rim protection. If Avery gets best inside, he gets penalized by a likely made hoop. If Dwyane Wade gets beat, Hassan Whiteside cleans up his mess.

Similarly, a lot of RPM is a fancy formula for +/-. This rewards players who are clearly better than their backup. However, we are a deep team with good defenders. If Smart subs in for Avery, the defense doesn't lose a step, so the RPM formula says his defensive impact isn't significant. That's not true, of course.

[PhoSita]

Defensive stats are largely bunk. They don't adequately take into account things like rim protection. If Avery gets best inside, he gets penalized by a likely made hoop. If Dwyane Wade gets beat, Hassan Whiteside cleans up his mess.

Similarly, a lot of RPM is a fancy formula for +/-. This rewards players who are clearly better than their backup. However, we are a deep team with good defenders. If Smart subs in for Avery, the defense doesn't lose a step, so the RPM formula says his defensive impact isn't significant. That's not true, of course.

My takeaway with RPM is that you have to look at it within the context of each team, even though it purports to control for every type of context.

Within the context of the Celtics, RPM says Bradley is not an indispensable defender, even though that does not preclude him from still being a very good defender in a vacuum who might be indispensable on a different team.

[mmmmm]

Defensive stats are largely bunk. They don't adequately take into account things like rim protection. If Avery gets best inside, he gets penalized by a likely made hoop. If Dwyane Wade gets beat, Hassan Whiteside cleans up his mess.

Similarly, a lot of RPM is a fancy formula for +/-. This rewards players who are clearly better than their backup. However, we are a deep team with good defenders. If Smart subs in for Avery, the defense doesn't lose a step, so the RPM formula says his defensive impact isn't significant. That's not true, of course.

My takeaway with RPM is that you have to look at it within the context of each team, even though it purports to control for every type of context.

Within the context of the Celtics, RPM says Bradley is not an indispensable defender, even though that does not preclude him from still being a very good defender in a vacuum who might be indispensable on a different team.

RAPM is a terribly useless stat as far as the Celtics as a whole are concerned.  It is riddled with collinearity effects that basically make both DRPM and ORPM pretty much worthless.

Offensively, "The Isaiah Effect^TM" dominates.  Guys who play more with him have FAR better offensive +/- numbers and net +/- numbers.   And attempts by the RAPM algorithm to correct for that are futile.  Consider that Jae has played something like 80% of his minutes with Isaiah.  And Isaiah has played something like 60% of his minutes with Jae.  So any 'difference' between their RAPM numbers is ultimately based on the small samples of playing time _without_ each other.   And Isaiah basically ends up playing a larger share of his minutes with crappier replacements for Jae while Jae plays only a tiny share of his minutes with a crappy replacement for Isaiah.

Avery takes a real beating.  Because of all the starters, he plays the most minutes with the bench.  This kills his net ratings on both the offensive and defensive end.   PLUS, his most frequent replacement in lineups is Marcus Smart.  So he gets no relative on/off boost on the defensive end like most starters do over their replacements.

Basically, RAPM is a crap stat as far as the Celtics roster goes.

[LarBrd33]

Isn't smart pretty weak in advanced defensive stats as well?

[alldaboston]

Isn't smart pretty weak in advanced defensive stats as well?

He's 6th among PGs in DRPM. I'm still so shocked that Avery is 47th...

[Csfan1984]

A factor for AB and Smart is an all game effort that keeps guys on their guard. It adds to defense that doesn't show up in advanced stats.

[Greyman]

Now, I could be off-base with this, especially because I'm not really all that competent when it comes to advanced stats, but I think it has to do mainly with a distinction between two types of great defenders.

There are two types of great defensive players: stoppers and defensive quarterbacks.

Smart, KG, Draymond Green - these are all examples of defensive quarterbacks. They're great individual defenders, but they also make their team better defensively simply by being on the court because they're great team defenders as well as individual defenders, which is why their advanced stats are generally very positive of them defensively.

People like Bradley, and to a lesser extent Tony Allen and Jae Crowder, are stoppers. They're phenomenal individual player/ball stoppers, and they can exceedingly limit their individual player that they're guarding. However, a lot of times this comes at the expense of some team defense, or at least they're so focused on limiting their individual guy that their team defense suffers.

I think this observation works well with Bradley, because you always see him in this type of defensive role. However, there are a lot of times that Bradley and Crowder get a little lost with their help/team defense; whereas, you hardly ever see that out of the defensive quarterbacks like Smart, Green, KG, etc. They're always in the right place at the right time.

Sound plausible?

I think there is a lot in this assessment. TP    This was shown in some analysis done here with links to youtube clips I think. AB does get dragged out of position on D at times.