Ranking the NBA's 20 Best Defenses of All Time

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It's not always easy to figure out how dominant an NBA defense is, especially when comparing modern-day units to the premier forces of the 1950s and '60s. 

Just looking at points given up isn't enough, because that doesn't allow pace to come into play. For that reason, defensive rating—a pace-neutral metric that shows how many points a team allows per 100 possessions—is a much better gauge to measure prowess on that end of the court.

But when attempting to rank teams historically, as we're doing here, that's still not good enough. After all, not every team with identical defensive ratings is on the same level. 

If two teams give up 95 points per 100 possessions, which is better—Team A, which did so during a year in which offenses thrived, or Team B, which did so when everyone was preventing points in admirable fashion?

Team A should be the easy answer, because context is crucially important. That, in a nutshell, is why DRtng+, or adjusted defensive rating, is the best inter-era metric for comparing defensive performances. 

Calculating it isn't particularly troublesome: Just divide the league-average defensive rating from the year in question by the team's defensive rating, then multiply the result by 100. If a team allows an opponent to score 10 percent more than the average squad that year, it'll have a 90 DRtng+. If it allows 10 percent fewer points per 100 possessions, it'll have a 110 DRtng+. 

A score of 100 means the defense was perfectly average. That does tend to happen surprisingly often, given that we're working with the 1,315 teams throughout league history for which we have data. Most recently, the 2013-14 Phoenix Suns were as average as could be on defense.

When determining the 20 best point-preventing units throughout the NBA's many seasons, the style of play doesn't factor into the equation. Neither does points allowed per game. Nor does memorability, subjectivity or the team's win-loss records. 

DRtng+ is all that comes into play. Analyses like this have been run before, notably by Hardwood Paroxysm's Andrew Lynch and Ian Levy, but this is taking it to a whole new level by running things before and after the 1976 ABA/NBA merger. 

Note: All stats, unless otherwise indicated, come from Basketball-Reference.com. This introduction is an adapted form of what was used when ranking the top 20 offenses in NBA history.

Joe Murphy/Getty Images

Defensive Rating: 100.3

League-Average Defensive Rating: 107.3

Win-Loss Record: 62-20

You knew Tom Thibodeau would show up at some point, and this is the best defensive team he ever coached. Interestingly enough, it was also his first season in charge of the Chicago Bulls, which explains a lot. 

Thibodeau caught the league by surprise.

He immediately implemented his defensive system of packing the paint, bringing over constant weak-side help and daring officials to whistle the Bulls for a lane violation. No one was prepared for it because it was such a novel approach, at least to employ those principles to such a ridiculous extreme. 

Derrick Rose, Luol Deng and Keith Bogans were all mainstays in the starting five for this squad, one that allowed opponents to score only 100.3 points per 100 possessions during a strong offensive season. However, the rest of the rotation was in flux, due largely to injuries. Losing Carlos Boozer wasn't a huge deal (for the defense, at least), but Thibodeau's Bulls overcame Joakim Noah's absence by maximizing Kurt Thomas' impact. 

Throughout the entire season, only 15 times did the opponent break into triple figures during regulation. Meanwhile, the Bulls held their foes below 80 a dozen times. 

Honorable Mentions: 2010-11 Boston Celtics (106.98 DRtng+), 2006-07 Chicago Bulls (106.93), 1963-64 San Francisco Warriors (106.77), 1958-59 Boston Celtics (107.75), 2005-06 San Antonio Spurs (106.63)

Jim McKnight/Associated Press

Defensive Rating: 91.3

League-Average Defensive Rating: 97.7

Win-Loss Record: 60-22

The 1974-75 Washington Bullets are the first of the pre-merger teams to show up, but they won't be the last. Defenses ruled the early years of the Association, and offenses have been taking over with increasing frequency as we get closer to the present day. 

Just look at the differences between the two league-average defensive ratings you've already seen. In 1974-75, the typical NBA squad allowed 97.7 points per 100 possessions. Thirty-six years later, that number had risen all the way to 107.3. 

Nonetheless, these Bullets still stood out in a big way. 

What made them so dominant was an incredibly potent interior, one comprised of Elvin Hayes and Wes Unseld. Both big men were capable rim protectors, and they each posted an 88 defensive rating that trailed only the seldom-used Dennis DuVal, whose rookie season seems like an aberration after his follow-up campaign with the Atlanta Hawks.

Opponents were forced to let fly from the outside, where they were greeted by Phil Chenier and Kevin Porter, two solid defenders in their own right. The combination led to opponents shooting 43.8 percent against these Bullets, the best defensive mark in the entire league.  

Bob Schutz/Associated Press

Defensive Rating: 92.4

League-Average Defensive Rating: 99.0

Win-Loss Record: 60-22

The New York Knicks won it all in 1970, one of two teams in franchise history to hold up the ultimate prize. And these 'Bockers achieved their goals with a suffocating defense that was led by All-Star guard Walt Frazier. 

Frazier remains to this day one of history's best defensive point guards, as he was a tenacious, physical player with quick hands. He racked up the steals by luring players into a false sense of security before pouncing and snatching the rock away, becoming one of the NBA's first players to turn thievery into a true art form. 

Unfortunately, we have limited statistical data on teams that played this early in NBA history, but the names still resonate to this day. Having a stellar defensive point guard, forward and big man is always a good combination, and that's exactly what New York boasted in 1969-70. 

Frazier was the leader of this team, but we can't overlook Dave DeBusschere and Willis Reed. After all, each of the three made the All-Defensive First Team that season. That squad debuted the year before, and it was already the second nod for both DeBusschere (who would finish his career with six selections) and Frazier (the only player to make the first team in each of the first seven years the honor honor was presented). Reed, meanwhile, would retire with only the one berth. 

Dick Raphael/Getty Images

Defensive Rating: 89.1

League-Average Defensive Rating: 95.5

Win-Loss Record: 48-34

Even at 34 years old and playing the final season of his illustrious career, Bill Russell was a game-changer on the defensive end of the court. He had to be, as this was an old Boston Celtics squad that still managed to advance all the way to the 1969 NBA Finals, where it knocked off the Los Angeles Lakers in a seven-game series. 

Russell wasn't the only stalwart, though. 

John Havlicek, still just 28 years old at the time, enjoyed a fantastic defensive campaign, earning 6.3 win shares on the less glamorous end and wreaking havoc with his understated athleticism and versatile play. Meanwhile, Tom Sanders could protect the rim when Russell was drawn away from the hoop, and just about every other contributor was an above-average defender. 

The league was incredibly fast-paced in 1968-69, with the average team checking in at 116.9 possessions per 48 minutes. To put that in perspective, the 2013-14 season saw the typical squad use 93.9 possessions over the same time frame. 

You might be surprised to hear that Boston allowed 105.4 points per game, but look at that defensive rating again. When pace is taken out of the equation, this was one of the most suffocating squads of all time. 

Dick Raphael/Getty Images

Defensive Rating: 84.9

League-Average Defensive Rating: 91.1

Win-Loss Record: 59-16

Here's another example of why pace matters so much. 

There were only eight teams in the NBA during the 1959-60 season, and the Boston Celtics actually allowed the fifth-most points per game: 116.2. The Philadelphia Warriors (116.0), Detroit Pistons (115.0), Minneapolis Lakers (111.5) and St. Louis Hawks (110.7) all allowed fewer, but they also slowed the game down a lot more than Red Auerbach's C's. 

Boston played at the fastest pace in the league, so that naturally resulted in more possessions for its opponents. And that's why the Celtics still boasted an 84.9 defensive rating, which you'll recall is a way of expressing how many points were allowed per 100 possessions. Thing is, when you're averaging 136.3 possessions per 48 minutes, that defensive rating is akin to how many points you're giving up over the course of 35 minutes and 13 seconds. 

Compare that to the 2013-14 Boston Celtics. By averaging 93.3 possessions per 48 minutes, their defensive rating represents how many points they're giving up during the average 51 minutes and 27 seconds. 

That's a big difference, and it shows why per-game stats can be ridiculously misleading. The league changes over time, and we have to account for that. 

Bill Russell, Bob Cousy, Tom Heinsohn and Frank Ramsey—among others—wouldn't have it any other way. 

D. Clarke Evans/Getty Images

Defensive Rating: 98.8

League-Average Defensive Rating: 106.1

Win-Loss Record: 59-23

With modern teams, we have the luxury of looking at the four defensive factors—effective field-goal percentage, turnover percentage, defensive rebounding percentage and free throws per field-goal attempt—and gaining more insight into the specific strengths of the point-preventing unit. 

Usually, even the greatest teams have at least one weakness, but the San Antonio Spurs are one of the exceptions to the rule. 

They were worst at letting opposing players get to the charity stripe, finishing "only" No. 11 in that category. Meanwhile, they forced turnovers at the sixth-best rate, rebounded better on the defensive end than all but two teams in the Association and held opponents to the worst shooting percentage in the NBA.

Tim Duncan anchored the interior of this defense, but his supporting cast wasn't too shabby. Tony Parker and Manu Ginobili had fresh legs on the perimeter at this stage of their respective careers, and it's impossible to look past the immense contributions of Bruce Bowen. 

Was Bowen a dirty player? Maybe, but that doesn't effect the numbers or the perception of these Spurs. 

When Gregg Popovich was recently made aware of a comparison between Bowen and Kawhi Leonard, he gave one of his trademark responses, one that was honest through and through, via Dave McMenamin of ESPN Los Angeles: "He's a lot better than Bruce Bowen. Bruce Bowen couldn't dribble and couldn't pass. He shot threes in the corner and he played good D, he played great D. So we want Kawhi to match Bruce's great D first and foremost, but after that he's a much better offensive player."

Fortunately for Bowen, his offense doesn't really matter here. 

Rocky Widner/Getty Images

Defensive Rating: 99.3

League-Average Defensive Rating: 106.7

Win-Loss Record: 56-26

On Jan. 9, I published an article wondering whether the Indiana Pacers had a chance to become the greatest defensive unit of all time. At that point, it was a legitimate inquiry, and the results spoke quite well for the eventual No. 1 seed in the Eastern Conference. 

Through early January, the Pacers had allowed 95.5 points per 100 possessions, and the league-average mark was 105.2. That gave Indiana an adjusted defensive efficiency of 110.2, which is significantly better than the mark with which it finished the season.

In fact, 110.2 would not only rank right at the top of the modern era, but it would also trail only two teams throughout the history of the NBA. The Pacers had something to be extremely proud of at that point. 

They still do, but their ranking is now tempered by that late-season collapse. Other teams figured out how to draw Roy Hibbert away from the rim, where he was far less effective, and the rest of the defensive aces—Paul George, David West, Lance Stephenson and George Hill—began to wear out with increased responsibilities. 

However, after factoring in the decline, the Pacers still managed to submit one of the greatest defensive campaigns in recent memory. 

"Even from the sideline, you're not getting a great return on pick-and-rolls against the Pacers," wrote NBA.com's John Schuhmann during a fantastic breakdown of Indiana's biggest and best skill. "That's why they rank as one of the best defenses we've ever seen."

That last statement really isn't the least bit hyperbolic. 

Ken Regan/Getty Images

Defensive Rating: 88.3

League-Average Defensive Rating: 94.9

Win-Loss Record: 54-26

Back to Boston we go. 

At this point in Bill Russell's career—he's listed at 31 years old during the 1965-66 season—the Celtics no longer ran such an up-tempo offense. In fact, four teams throughout the smaller Association ran more possessions per 48 minutes than Russell's Celtics did.

It didn't matter. 

Of the nine teams in the league, Boston ranked No. 8 in offensive rating. Red Auerbach couldn't get his players to the free-throw line, and they made only 41.7 percent of their field-goal attempts, a mark that beat out just the 22-58 Detroit Pistons. 

Nonetheless, Boston won 54 games, relying heavily on the strength of their ridiculously effective defense. 

Triple-digit scores were the norm during the 1965-66 season. Even the lackluster Beantown offense scored at least 100 points in all but 11 of its 80 games. But it wasn't the norm for the Celtics' opponents. 

On 23 separate occasions, Russell and Co. held the other squad to double figures. During the postseason, they did so three times more, two of which came against Wilt Chamberlain and the Philadelphia 76ers.

Then again, shouldn't that be expected when Russell is joined by K.C. Jones, John Havlicek, Sam Jones, Tom Sanders and Don Nelson?  

Andrew D. Bernstein/Getty Images

Defensive Rating: 95.0

League-Average Defensive Rating: 102.2

Win-Loss Record: 37-13

The 1998-99 San Antonio Spurs were all about the two men in the middle. 

A 33-year-old David Robinson anchored the paint and used his still-present athleticism to protect the rim, earning himself an 87.9 defensive rating and 4.4 defensive win shares. The former was the best mark in the league, while the latter trailed that of only one player during this lockout-shortened season. 

Next to him, a 22-year-old Tim Duncan thrived. 

Duncan had some impressive statistics of his own: a 91.5 defensive rating that left him behind only Robinson and Patrick Ewing, as well as 4.7 defensive win shares, which paced the league. Yes, that is correct. The Spurs had the No. 1 and No. 2 finishers in that category, with the Atlanta Hawks' Dikembe Mutombo filling up the podium with his 4.2 defensive win shares. 

Even though these Spurs didn't force many turnovers and sometimes struggled to keep teams off the offensive glass, they completely shut down the opposition, forcing them into bad shots and doing so without fouling. It was a brutal combination, especially during a lockout-shortened season that made offenses all the more dysfunctional. 

And that's the other point. 

The league-average defensive rating of 102.2 stands out as an aberration. It's sandwiched by a 105.0 rating the year before and a 104.1 mark the year after. So, what if we pretended this was a full 82-game season, which would allow for offenses to pick up the slack toward the end of the year, when defenses were tired and offensive chemistry stood to be much better? 

If we assume the Spurs maintain their 95.0 defensive rating, and the league average goes up to an arbitrary 104.5, San Antonio's DRtng+ suddenly becomes a flat 110. That would allow Duncan, Robinson and the rest of these Spurs to earn the No. 3 spot in this countdown, if only by an ultra-slim margin.

Nathaniel S. Butler/Getty Images

Defensive Rating: 95.4

League-Average Defensive Rating: 102.9

Win-Loss Record: 54-28

Now we come to one of the defenses that's typically mentioned in the conversation centering around the greatest point-preventing units of all time. The 2003-04 Detroit Pistons were fearsome, playing tough, physical defense and offering no refuge on any area of the court. 

Ben Wallace was squarely in the midst of his prime, asserting himself as one of the best defenders we'd ever seen. A 23-year-old Tayshaun Prince wreaked havoc with his length, while Rip Hamilton and Chauncey Billups were both pests out on the perimeter. 

It was a legendary combination of talents, and the reputation was only aided when Detroit won the title without boasting the services of a true offensive superstar. 

So, why are these Pistons not even in the top 10? Well, context is important. To illustrate that point, I'll use the same quote I shared in the ranking of the league's best offenses, coming from Andrew Lynch of Hardwood Paroxysm:

But 2004 was a year of defense. The league average efficiency was 102.9 in 2004, the lowest it's been since 1979. Hand-checking would be curtailed and defensive three-second violations enforced the following year in an attempt to bring some offense back to the game.

Allowing 95.4 points per 100 possessions is incredible. But doing so while the league as a whole is only scoring 102.9 over the same span diminishes the impressiveness. 

Plus, there's a second problem with calling these Pistons the greatest defenders of all time.

They didn't even rank No. 1 in 2003-04. 

Andrew D. Bernstein/Getty Images

Defensive Rating: 98.2

League-Average Defensive Rating: 106.3

Win-Loss Record: 57-25

Let's not forget just how good Patrick Ewing was at shutting down the other team while he was still in his prime. 

Of course, it also helped that he spent the 1993-94 season playing alongside Charles Oakley, Greg Anthony and John Starks, all of whom were standout defenders in their own right. In fact, only Oakley received any Defensive Player of the Year votes this season, and he was also the team's lone representative on the All-Defensive squads. 

"I still to this day believe Oakley was good only because he scared people," Bleacher Report's Dan Favale told me when we were discussing these mid-'90s Knicks. 

Nonetheless, and regardless of the method and Halloween factor, this was a team effort. The Knicks just weren't going to let the opposition score from the field. In 1993-94, New York allowed opponents to post an effective field-goal percentage of just 45.1 percent, which was easily the best mark in the league.

How good is that? Well, effective field-goal percentage gives extra weight to three-point buckets, seeing as they're worth an extra point. Despite that, a 45.1 field-goal percentage (New York actually allowed 43.1 percent) still would've been the No. 6 mark in the league. 

At the same time, the Knicks also forced turnovers on a higher percentage of possessions than all but two NBA teams, and they simultaneously were the best on the defensive glass. There was just no way to keep control of the ball, make shots from the field or gain extra possessions with offensive boards.

But you may have noticed I keep specifying "from the field."

The Knicks finished No. 21 in free throws allowed per field-goal attempt, thanks to the contact-heavy proclivities of just about everyone on the roster. Four players—Ewing, Oakley, Charles Smith and Starks—actually averaged more than three personal fouls per game.  

Nathaniel S. Butler/Getty Images

Defensive Rating: 99.7

League-Average Defensive Rating: 108.0

Win-Loss Record: 60-22

What was the difference between the 1992-93 New York Knicks and the squad you just read about? 

Health and relative youth, for starters. 

Patrick Ewing (30 during the 1992-93 season), Anthony Mason (26), Charles Oakley (29) and John Starks (27) were all at the stage of their careers when that extra year helped out immensely, and they also came together to play more games than they would the next season. In 1992-93, that quartet missed a combined four games throughout the entire season. In 1993-94, they sat out a combined 35 outings, which is obviously a significantly higher number. 

The strategies of the teams were largely similar: Both focused on deterring shots at the expense of fouling, both caused plenty of turnovers and both were incredibly adept at ending possessions with defensive rebounds. 

However, having the key members around throughout nearly the entire season made a big difference, even during a more offense-minded season. It allowed these Knicks to thwart opponents at a ridiculous clip, holding them to a minuscule effective field-goal percentage of 44.4 percent. 

Just as we did with the '93-94 Knicks, let's see how that would rank if it were a field-goal percentage, not an effective field-goal percentage. 

New York (as you might have guessed) had the best field-goal percentage allowed in '92-93—42.6 percent. That's the only mark the effective field-goal percentage wouldn't have topped, as No. 2 was the Orlando Magic, who allowed opponents to make 45.6 percent of their shots from the field. 

How's that for impressive?

Jesse D. Garrabrant/Getty Images

Defensive Rating: 98.9

League-Average Defensive Rating: 107.5

Win-Loss Record: 66-16

It's not supposed to be this easy. 

In 2006-07, Ray Allen was still on the Seattle SuperSonics. Kevin Garnett was still thriving with the Minnesota Timberwolves. Doc Rivers, Rajon Rondo and Paul Pierce had put together a miserable campaign in which they managed to win only 24 games. 

But it all came together perfectly after general manager Danny Ainge assembled the Big Three in just a single summer. 

Right away, the C's held the Washington Wizards to 83 points to open the schedule. Then the Toronto Raptors mustered up only 95 points in an overtime victory for Boston. It wasn't until the ninth game of the season that Boston would drop a contest, and it allowed only five triple-digit performances before the calendars flipped over to February. 

On Nov. 29, the Celtics even held the New York Knicks to just 59 points. 

Everything worked right off the bat, which is quite the rarity for a newly assembled team with so many prominent pieces trying to figure out their roles. If anything speaks to Garnett's greatness on the inside, Pierce's underrated perimeter defense and Rondo's hounding nature, it's that. 

Boston actually finished the season ranked No. 1 in effective field-goal percentage allowed and in percentage of turnovers forced. It was just brutally difficult to put up points against this squad without getting to the charity stripe. 

NBA Photos/Getty Images

Defensive Rating: 84.5

League-Average Defensive Rating: 92.1

Win-Loss Record: 57-22

The man at the center was pretty darn good at this whole defense thing. And while we're talking about the team photo, can we note how the tradition of holding up a picture of absent team members should be continued in the present day? 

During the 1960-61 season, Bill Russell was right in the midst of his defensive prime. A 26-year-old with an innate understanding of positioning, the big man prided himself on holding his opponent to the lowest total possible, and it showed on a nightly basis. He earned 11.3 defensive win shares this year, a mark higher than any other player in NBA history has produced in a single season. 

Of course, it's only Russell's sixth-best mark, but that's another story.

Whenever these Celtics with a cigar-smoking coach have come up, pace has been important. So let's refer to that once more.

In 1960-61, Boston had the fastest pace in the NBA and still allowed the second-fewest points per game, which is a remarkably deadly combination. The defensive rating of 84.5 wasn't just tops in the league; it was 4.2 points per 100 possessions better than the St. Louis Hawks and the rest of the eight-team league.

Bob Cousy had the best defensive season of his career (statistically speaking), while Tom Heinsohn, Sam Jones, Frank Ramsey, K.C. Jones and...well, let's be real...everyone on the roster played excellently as well.

Nonetheless, it was still all about Russell.  

Fernando Medina/Getty Images

Defensive Rating: 94.1

League-Average Defensive Rating: 102.9

Win-Loss Record: 57-25

Even with the NBA as a whole struggling to score points during the 2003-04 season, the San Antonio Spurs were just that good. In fact, they're the best post-merger defense, narrowly beating out the 2007-08 Boston Celtics, the Detroit Pistons from this same season and the Patrick Ewing-led New York Knicks. 

The collection of talent on this squad was just ridiculous. In fact, San Antonio was the only team in the league with two All-Defensive selections, as Bruce Bowen earned a first team nod while Tim Duncan was on the lesser squad. Bowen actually managed to finish fourth in the Defensive Player of the Year voting, and his bigger teammate was three spots behind him. 

But let's not forget about everyone else. 

Rasho Nesterovic and Hedo Turkoglu were both in their primes, and it showed, given the way they moved around the court and used their size to their advantage. Manu Ginobili was a pesky defender, as was Tony Parker, then playing in just his third NBA season. 

With all those players at Gregg Popovich's disposal, the Spurs finished top 10 in each of the four defensive factors—first in effective field-goal percentage and defensive rebounding percentage, ninth in free throws per field-goal attempt and 10th in turnover percentage. 

It's tough to beat that combination, and not many teams did. 

Throughout the entire '03-04 campaign, only seven times did the Spurs give up at least 100 points. Five of those outings saw the total rise no higher than 103. One was a 115-point game by the Dallas Mavericks (who ranked as the top offense of all time, mind you), and another was a 120-point performance by the Los Angeles Lakers, who scored 19 of those points in two overtime periods. 

Uncredited/Associated Press

Defensive Rating: 79.3

League-Average Defensive Rating: 86.9

Win-Loss Record: 40-26

Offense was hard to come by during the 1951-52 season, and during the early years of the NBA in general. With 10 teams in the league, the average defensive rating was only 86.9 points per 100 possessions, and it would steadily trend upward for decades. 

But even with that microscopic average serving as the basis for comparison, these Minneapolis Lakers still managed to stand out. They allowed just 79.3 points per 100 possessions, which is an absolutely ridiculous number. 

In fact, of the 1,315 teams that were analyzed for these rankings, the '51-52 Lakers had the best raw defensive rating. They were actually the only team below 80, with the previous year's iteration (when the league average was an even-lower 85.1) serving as the silver medalists in that category by allowing 80.7 points per 100 possessions. 

What made these Lakers so good? The answer is pretty simple. 

Everything. 

George Mikan finished first in defensive win shares during the 1951-52 season, earning 8.0 by himself. Vern Mikkelsen and Jim Pollard each had 6.6. Slater Martin finished fourth with 4.5 defensive win shares. 

All of them played for the Lakers. 

WCC/Associated Press

Defensive Rating: 87.4

League-Average Defensive Rating: 95.9

Win-Loss Record: 58-22

It's Bill Russell again. 

Once more, the Boston Celtics led the NBA in pace (127.3 possessions per 48 minutes) and still managed to keep their opponents' scoring in check. They allowed 111.6 points per game, a mark better than that produced by every team but the Bob Pettit-led St. Louis Hawks. 

This time, Russell earned an insane 12.6 defensive win shares. Astoundingly, that was more than double that produced by anyone else in the NBA, as this was the full top five: 

1. Bill Russell, 12.6
2. Bob Pettit, 5.8
3. Elgin Baylor, 5.1
4. Bob Cousy, 5.1
5. Wilt Chamberlain, 5.0

Oh, and this was still only the third-best season of Russell's career, when sorting them solely by defensive win shares. 

Even though everyone in the league was routinely breaking past the 100-point barrier—the worst per-game average belonged to the St. Louis Hawks at 109.6—the Celtics still managed to keep their opponents in double figures on 18 different occasions.

And it wasn't just Boston feasting on the low-scoring teams in the Association; it even included the offensively potent Syracuse Nationals and Cincinnati Royals among its victims. 

Anonymous/Associated Press

Defensive Rating: 85.1

League-Average Defensive Rating: 93.6

Win-Loss Record: 60-20

The 1961-62 season was actually a little bit different. 

This time, Boston didn't attempt to run everyone out of the gym. It still finished with a remarkably quick pace, but the Philadelphia Warriors, led by Wilt Chamberlain and Paul Arizin, played even faster. Additionally, the Celtics allowed fewer points per game than anyone else. 

The highlight of the season actually came against Philadelphia, featuring that infamous rivalry between Bill Russell and Chamberlain. 

The Warriors averaged a jaw-dropping 125.4 points per game in 1961-62, which allowed them to lead the league in scoring. But on Feb. 24, Boston completely shut down its biggest rival that season, holding Chamberlain to 26 points and the team as a whole to 86. 

Think about how impressive that is. The Celtics held Philadelphia to just 68.6 percent of their usual total. 

Was this a one-game aberration? Sure. But the Warriors scored 109 points or more in all but five of their games that season: 

1. 86 points against the Boston Celtics
2. 98 points against the Boston Celtics
3. 102 points against the Boston Celtics
4. 106 points against the Boston Celtics
5. 107 points against the Boston Celtics

Case in point? Case in point. 

Dick Raphael/Getty Images

Defensive Rating: 84.2

League-Average Defensive Rating: 93.6

Win-Loss Record: 62-18

Are you tired of Bill Russell and the Boston Celtics yet? 

At this point, you should probably realize that it doesn't really matter who was on the floor with him. He anchored dominant defenses early in his career, and he did the same late in his Boston tenure when the faces around him were largely different.

That said, the early-'60s teams were his best, as he was joined by an unsurpassed supporting cast of high-quality defenders.

K.C. Jones doesn't receive nearly enough credit for the work he did on the less-glamorous end of the court, Sam Jones was never a liability, and the frontcourt combination of Tom Heinsohn, Tom Sanders and John Havlicek insured that there was both depth and rim protection no matter where Russell was on the court. 

The six players I just mentioned all finished in the top eight for defensive win shares during the 1964-65 season, with only Wilt Chamberlain and Nate Thurmond interrupting the Boston-based proceedings. Willie Nauls also came in at No. 15, for what it's worth. 

These Celtics held opponents to under 100 points 26 times. During six of those outings, Boston's opponent was unable to muster up even 90 points. 

To put that in perspective, the league's other eight teams combined to hold their opponents below 90 points just 11 times.

Dick Raphael/Getty Images

Defensive Rating: 83.8

League-Average Defensive Rating: 94.6

Win-Loss Record: 59-21

Now that you see the Boston Celtics have completed their clean sweep of the podium, it's worth reflecting on just how dominant Bill Russell was. 

Not only did he anchor the top four defenses in NBA history, but he also plugged up the middle for eight of the top 20. Russell played 13 seasons, and his worst finish came in 1967-68, when Boston earned the No. 87 adjusted defensive efficiency of all time.

That means each and every one of his seasons was in at least the 93rd percentile. 

If that year was taken out of the equation, the remaining dozen would all be in the 95th percentile or better. Eleven of his 13 Boston seasons rank among the top 50 of all time. 

But this is the best of the bunch. And just as the 1964-65 season was a massive jump up from the rest of the field, so too does this one stand out above the previous entry in these rankings. 

Russell, 29 years old during the '63-64 campaign, earned 16 win shares on the defensive end, a mark that still stands out as the No. 1 season of all time. All the other top pieces we've been over time and time again were in place as well, and it was arguably K.C. Jones' finest year. 

On three separate occasions during this top-ranked season, Boston prevented the opposition from scoring even 80 points. And those games came against the Philadelphia Warriors and Los Angeles Lakers (twice). Three more times, teams failed to get to 90 against Red Auerbach's squad. 

If these rankings felt like a Russell lovefest, it's because they should. 

And this season, by a wide margin, was the crowning jewel in his incredible defensive career.