APBRmetrics

permaximum, I was neither referring to you, nor disagreeing with you on the basis point of Kobe Bryant's actual (as opposed to potential) defensive performance. To the contrary.

And now let me try to provide a bit of evidence for my (everyone's?) thesis that there is an energy budget constraint that imposes a significant trade-off between effort expended on offense and elite defensive performance. Specifically, let's look at Kobe Bryant-esque, high-volume shooters, across all positions, and see what their realized performance is at the defensive end.

During his NBA All-Defensive years, 1999-00 to 2011-12, KB averaged over 20 FGA per game. So, let's take that as the chucking threshold. And then let's consider DBPM as the defensive performance measure (not because it is the preferred measure, compared to DxRAPM, but because it is the best measure that is available over all the years of interest). And let's look at all complete years since 1979-80 (arbitrarily selected to correspond with perceptions of the "modern" NBA), so 36 seasons in all.

So, one question we can pose is: in all of these years, how many instances are there where high-volume shooting Forwards and Guards have the 1st through 4th highest DBPM, what we can consider as meriting "All-Defensive" 1st and 2nd team status, and, correspondingly, 1st and 2nd highest DBPM for Centers?

In short, the answer is "scant few'.

Anyone want to guess for Guards? Well, there's Michael Jordan, three times (seasons ending in 1988, 1989, and 1991) and Russell Westbrook in 2015. Regarding the latter however, there's a large anomaly between DBPM and RPM which gives him a rating of -0.71 as compared to 2.2. So, a question mark there, and frankly I'm a bit suspicious of MJ's numbers as well. Not just because the (quarter-based) 1991 xRAPM shows a rating of 1.1 as compared to a DBPM of 1.8, but because defense is a learned art, and I expect that MJ's early-career stats might be inflating his true value.

Top 4 DBPM Forwards? There are but two...and none since 1987. Larry Bird twice: in 1985 he ranked 3rd, and in 1987 4th. And then Dr. J in 1980 when he finished 4th.

And Top 2 Centers? Technically (by the rules imposed) there is but no instance in all 36 years, though the better argument is that one should count. The year in question is 1994, when Hakeem and David Robinson were ranked 3rd and 5th (with Dikembe ranked first) but a rather strong argument would be made that they were competing for 2nd Team All-NBA as the 2nd and 4th ranked players (Oliver Miller and Jon Koncak) played far fewer minutes. (And then in 1995, Hakeem was ranked third, just behind David Robinson who didn't meet the shot attempt threshold.)

So, there you have it for the heights of defensive accomplishment for high-volume shooters over the last 36 years: one guard - Michael Jordan, twice meriting 1st Team All-Defense and once 2nd Team; two forwards, with 2nd Team honors - Larry Bird twice and Dr. J once; and one center - Hakeem, getting one 2nd Team mention.

Summarized another way, over the last 36 years, there were 360 slots in total for 1st and 2nd Team Defensive honors. High-volume shooters, who tend to be the the most athletically gifted and physically impressive players in the league, "earned" but 2% of them. And none in the last 21 years!

Interesting, no?

I agree with that. Generally, high volume shooters use most of their energy on the offensive end by limiting the energy spent on the defensive end. All the examples I gave in the above post (besides Jordan) are not very-high usage guys. A player can be great at both ends of the floor but it's rare for a very-high usage player to be great at defensive end. Yes, I agree with that.

Kobe probably suffers from that and it only supports my thoughts on his all-defensive selections. If the voters considered his efforts on the offensive side of the game before they voted, it's been a comical award for a quite some time then.

I would like to revise and resubmit my results, this time putting Kobe Bryant-esque shot attempts on a per possession basis (what I really should have done in the first place) so as to account for changing game pace over the 36 years in question. So, same exercise, but the threshold now is the weird 26.7336 FGA per 100 possessions. (This is equivalent to 20 FGA/game, relative to KB's FGA/game over the 2000 to 2012 seasons; also a MPG of 20 is imposed to include only those near and actual starters who are of interest.)

Doing this doesn't substantively change the picture of high volume shooters exhibiting elite defensive performance, but it does (unsurprisingly) distribute the instances more evenly over the 36 year time frame.

So, what's the new summary of results, again, of free-shooting players at all positions having the 1st or 2nd best DBPM in any given year.

Centers:

This is perhaps the most interesting change, as there are now none. Note, however, that high-volume shooting centers are a rare phenomenon in the NBA, with only 17 player seasons (by 7 players) across the 36 years.

Forwards:

The picture now is that there are two, maybe three, seasons total. The Dr. J 1980 season remains, but Larry Bird's two seasons are eliminated (for his offensive load having been proportionately lower). Added to the list now is Kevin Garnett's 2003-04 season, where his 5.0 DBPM ranked 2nd among forwards (whereas his 5.6 DxRAPM ranked 3rd). Possibly also added to the list is LBJ's 2008-09 season, where his DBPM of 3.6 ranked 4th. However, the preferred DxRAPM has him at 2.8 and clearly out of the Top 4.

And, again, describing the eligible pool, there were 80 seasons, put forth by 33 players.

Guards:

Here the picture is of more Michael. Added to his list are the 1991-92 and 1995-96 seasons, where his DBPM were 1.7 and 1.2, respectively, good for a 4th place ranking, both years, among guards.

And new to the list is Dwyane Wade's 2009-10 season where he ranked 2nd with a 2.0 (tied for 3rd in DxRAPM with a 1.1)

And with all guards, there were 88 eligible seasons, put forth by 30 players.

So, in summary, players exhibiting Kobe Bryant-esque shooting rates, in the "modern" era of the NBA, have very much not tended to play truly elite defense over such seasons.

Discounting the "suspicious" LBJ entry, only 5.7% of players exhibiting qualifying shooting rates ever merited (one or more seasons) of 1st or 2nd Team All-D status, and this only occurred in 4.3% of the qualifying seasons.

And if your initials aren't MJ, the odds drop considerable, with only 1.8% of high shooting-volume seasons being accompanied by a deserved All-D mention.

And one final observation. The two clear results for forwards (with KG and Dr. J) these seasons barely qualified in terms of meeting the shooting threshold, whereas the guard results were comfortably over. This seems relevant to the overall story, primarily in terms of the difficulty of achieving the result.

It's also possible, likely even, that a real plus-minus measure detects a real defensive benefit from a super offensive player, even when that player may be mediocre on defense. If he causes the opponent to keep 'defensive specialists' on the floor to guard him, then his opponents are in general less offensively inclined.

In 32 regular-season meetings between Kobe and Bruce Bowen, 1998-2009, Kobe averaged 26 pts in 40 min (Bowen 8 pts on 7.6 shots in 32 mpg). Kobe had FG% = .426, 3fg% = .278, and needed 26.5 shot attempts per 26 pts.

In the same interval, RS Kobe avg'd 38 min and 26.5 pts on 24.6 TSA (.455 FG, .340 3FG%) in all RS games.
Bowen in all RS games avg'd 27.6 min with 6.1 pts on 6.1 TSA.

So Bowen's effect on Kobe's shots is pretty good, while Kobe doesn't affect Bowen much if any. But Bowen was on the floor another 5 mpg vs LA.
http://bkref.com/tiny/iz3U1

In the playoffs, they met 4 times ('02, '03, '04, '08) totaling 22 games. In this 7 year span, Bowen avg'd 31.2 mpg in RS, 32.9 in PO (117 G), and 33.7 vs the Lakers.

The extra minutes Bowen is on the floor just to defend Kobe are minutes a better offensive player -- Parker, Ginobili, Finley, Barry, Robinson -- is not in the mix.

A few additional, relevant words on the "sticky truth" that all defensive positions aren't created equal. First a general point, followed by a specific implication as to the defensive contributions of Kobe Bryant.

The "sticky truth" noted was that players "privileged" with defending the area nearest to the basket have the potential for the greatest defensive contributions, as that is where the best shots are both realized and prevented. The corollary, of course, is that those defending the zone where the second-best shots are realized are also privileged, increasingly so as shot attempts in that zone increase.

Said another way: one should expect that the defensive potential of wing-defending positions should increase with increasing shares of 3PAs.

If I've got the summary statistics correct, from 2001 to 2015, about 10% of FGA shifted across the arc (what was about 20% of those from 10 feet to the arc moving beyond it) according to B-R. That's a lot of additional higher quality shots to disrupt for a player who's defensively inclined and tasked with defending the perimeter.

Comparing DxRAPM/RPM for these two years, what you see is that the performance of guards - whose position on the court includes such responsibility - changed to reflect the opportunities in the changing shot distribution.

In particular, in 2000-01, only 12% of guards showed positive defensive +/- ratings. Fourteen years later, that share had risen to 30%. Correspondingly, the best performing guard's rating rose from 1.8 to 4.92.

And what does this evolution have to do with Kobe Bryant? Well, his "All-Defensive" career transpired during (most of) this same interval, and there is no real suggestion in his record that his rating improved, reflecting the underlying potential. But then again, defending the wing with excellence is very tiring, so we return to Sticky Truth #2: there's only so much energy available to spend on the basketball court.

Finally, let me switch gears and ask a question about an econometric point.

I have the sense that the significant changing "structure" of the game observed, i.e. rising 3PAr, ought to pose some econometric problems for DBPM. Is there any strong reason to believe that box score statistics would show a stable relationship with defensive contributions for wing defenders (especially) with such a dramatic change in the way the game is played? Or am I misrepresenting DBPM?

What I see in the data, comparing DxRAPM/RPM with DBPM ratings for guards, is that 2000-01 shows low average discrepancies (i.e. "DxRAPM - DBPM") for both DxRAPM "positive" and "negative" players: +0.21 and -0.02, respectively.

Contrast this with last year's data, where average "RPM - DBPM" shows +1.12 for the players with ratings above zero and -0.34 for those below.