trex_8063 wrote:As much as people are saying we shouldn’t even think about this one, I do think a case CAN be made for someone other than Bill Russell.  I won’t deny that NO ONE has had as much defensive impact as he did (or perhaps even particularly close); but as SinceGatlingWasARookie implied, one could fashion an argument around question-marks pertaining to era.  Aside from questions on strength of era, let’s also take note of the relatively “smaller court”, which would allow a rim-protector who can cover a little ground a lot of latitude to effect the game defensively.  In an era where a 20ft was considered a long/outside shot, and beyond that not typically thought of as a threat, there’s literally only about ⅔ the surface area of court that the defense has to effectively cover in Russell’s time compared to present day.  With a more tightly-packed halfcourt, I think a player like Rudy Gobert would have a larger defensive impact in that scenario than he does today, for example.  Would it match Russell’s?  Idk, perhaps not, but just putting that out there. 
Looking at a guy like David Robinson, I could potentially see him matching Russell’s impact in that time period, IF he had the mind to play like that.  This is an important component of the case for Bill Russell, though:  he was somewhat a unicorn in his time.  He broke [or at least modified] many of the “rules” that were taken for granted about how a big-man should be and should play defense.  He did so because he [and Auerbach, too] was a studious, thinking player, who sought out ways to be more effective defensively (even if they rubbed against conventional wisdom of the time). 
In doing so, he essentially created the blue-print for the modern defensive big.  If there had been no Bill Russell, and David Robinson had been born 30 years earlier, would David Robinson have had the basketball intellect to rewrite things as Russell did?  Obviously we’ll never know, but we certainly cannot just assume that he would.  DRob certainly had all of the necessary physical tools, though (one could even argue that Robinson was a marginally BETTER all-around athlete).  
But there were other guys in that time with all the physical tools, too.  There was, at the very least, one other phenomenal athlete in Russell’s time; a person whose athleticism is questioned by virtually no one:  Wilt Chamberlain.  Granted, defense often wasn’t Wilt’s focus; but even when it was, he never matched the defensive performance of most Russell-anchored teams.  The single-best defensive team Wilt ever anchored was a -6.0 rDRTG (in ‘64).  That was with a rookie Nate Thurmond (another fine athlete and fine defensive big) playing 26 mpg, and Al Attles (a defensive specialist) playing 27 mpg at PG.  That was the best team defense Nate Thurmond was ever a part of, too (with or without Wilt); in fact, the best defense strictly Thurmond-anchored was just -3.3 rDRTG (and that was with a backcourt of Norm Van Lier and Jerry Sloan, plus Bob Love at PF).  Even that -6.0 mark in ‘64 is still less than what Russell’s teams were AVERAGING over a 13-year period:  the AVERAGE Celtics defense in Russell’s career was -6.9 rDRTG.
When a 35-year-old Russell decided to hang up his sneakers, the Celtics defense fell off by a somewhat shocking +6.3 (this was a team that still had prime John Havlicek and Tom Sanders).  The best team defense the Celtics managed in the 70’s was a -5.8 rDRTG in ‘73:  that just four years from Russell’s career, and arguably in a weaker ABA/expansion-diluted league…...and that’s with Dave Cowens up front with Paul Silas and John Havlicek, Don Chaney and Jo Jo White in the backcourt.  White is arguably the weakest defender in that starting core, and even he’s pretty decent to my eye (he looks marginally better than Hondo at times).  But the very best that core managed together was still a little less than the last Russell [last legs?] anchored defense.
And when we have all these “bridger” guys like Kareem who straddle multiple eras, with whom we can play the six degrees of separation game to the modern era…...idk, it’s hard to not look at Russell as a true outlier in defensive impact, even with era considerations. 
As such, vote Bill Russell (though I do think it’s closer than some people imply).
How can I find a list of teams with the best rDRTG? I’m curious what the numbers are for the best defensive teams of all time.