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The "best ever" tag isn't something that should be thrown around lightly in the NBA, but it's time we start at least thinking about applying it to the suffocating defense boasted by the Indiana Pacers during the 2013-14 season.

Roy Hibbert is the defensive headliner, protecting the rim magnificently while he shows off his mastery of the verticality principles.

According to NBA.com's SportVU data, the 7-footer from Georgetown faces 9.3 attempts per game at the rim, and he's holding opponents to only 40.4 percent shooting there. Among qualified players (at least 20 games played, at least six rim attempts per game faced), no one keeps opponents to a lower percentage.

But the beauty of Indiana's defense is that it's not all about Hibbert.

Paul George has developed into one of the best perimeter stoppers in basketball, and he has the versatility to play in the paint as well. The toughness and physicality of David West has set a tone in the post, and he's a phenomenal floor general on the less glamorous end. George Hill is one of the better defensive point guards in the NBA, and the list goes on.

The combined effort is a unit that allows only 88.6 points per game, routinely leaving opponents scratching their heads and wondering how in the world they're supposed to score against Frank Vogel's suffocating schemes.

At this point, it's really not fair to compare the Pacers to the other teams in the NBA this season.

The Chicago Bulls allow the second-fewest points per game, and they're still 3.4 behind Indiana. Checking in at a distant third are the Charlotte Bobcats, owners of a defense that gives up 95.8 points per game.

Even when we take pace out of the equation, Indiana reigns supreme by a large margin. Here are the top five squads in defensive rating, per Basketball-Reference:

Again, it's not even close.

The gap between Indiana and Chicago (4.6 points per 100 possessions) is actually as big as the one between the Bulls and the Phoenix Suns. The Suns sit at No. 12 in the rankings.

See why we have to turn to comparisons from the past?

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Throughout the duration of the NBA's history, no team has allowed fewer points per game than the 1998-99 Atlanta Hawks, so that seems like a good place to start.

Led by Dikembe Mutombo during the lockout-shortened season, the Hawks held opponents to only 83.4 points during the average contest en route to a 31-19 record that would earn them the No. 4 seed in the Eastern Conference. Though they'd be swept by the New York Knicks in the second round of the playoffs, they can always brag about their record.

But it's not as impressive as it sounds.

The NBA played at a ridiculously slow pace that season, thanks primarily to a different style of basketball and the aftermath of a lengthy offseason that left players getting back into shape during the season. Only two teams allowed more than 100 points per game (compared to 17 this year), and the Sacramento Kings were the only team to break into triple digits in points scored per contest. Their 100.2 points per game would rank in the bottom half of the league this season.

That's why it's important to account for pace when making historical comparisons.

Points per game is almost completely irrelevant, as it doesn't factor in how quickly (or slowly) teams were playing. That's why we'll be focusing on defensive rating (points allowed per 100 possessions, a pace-neutral stat) when culling the list of candidates for best defense of all time.

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Throughout the relevant part of NBA history, these are the only teams to produce defensive ratings of 97 or lower:

2003-04 San Antonio Spurs, 94.1 1998-99 San Antonio Spurs, 95.0 2003-04 Detroit Pistons, 95.4 2013-14 Indiana Pacers, 95.5 1976-77 Denver Nuggets, 96.1 1977-78 Phoenix Suns, 97.0

What do I mean when I say relevant? Well, we're only counting numbers generated after the NBA-ABA merger in 1976, as the league received a serious influx of talent and became much more like modern basketball.

Sorry, Bill Russell and the old-school Boston Celtics.

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As impressive as the 84.5 defensive rating was in 1958-59, for example, the worst mark in the league was 95.0, belonging to the Cincinnati Royals.

But let's trim even more fat.

The three-point shot wasn't around until the 1979-80 season, so naturally, it was easier for teams before that campaign to hold opponents to more impressive scoring rates. When the maximum number of points on a possession was two rather than three, defensive ratings were obviously going to be lower. So that eliminates the 1976-77 Denver Nuggets and the 1977-78 Phoenix Suns from contention.

Now we're left with four candidates, and you'll note the Pacers are still alive. For what it's worth, that aforementioned Hawks squad had a defensive rating of 97.1; they weren't even the top defense the year they set the all-time record for fewest points allowed per game.

MLB sabermetrics have adapted a number of era-adjusted stats, and I'm about to follow suit, using the example of ERA+.

ERA+ is a more advanced version of ERA, and it's rather simple to derive. All you do (assuming you aren't taking park factors into account), is divide the league ERA by the individual ERA. For example, with a 2.5 ERA during a year in which the league-average mark was 4.5, ERA+ would be calculated as such: 4.5/2.5 = 1.8 ERA+.

Because a lower number is more ideal for ERA (just like with defensive rating), the higher the ERA+, the better. It means the individual is that much better than the average, and a comparison to the average mark allows us to make inter-era judgments.

With that in mind, let's create the defensive rating+ for each of the remaining four candidates:

Team Year Defensive Rating League-Average Defensive Rating Defensive Rating+ San Antonio Spurs 2003-04 94.1 102.9 1.094 San Antonio Spurs 1998-99 95.0 102.2 1.076 Detroit Pistons 2003-04 95.4 102.9 1.079 Indiana Pacers 2013-14 95.5 105.2 1.102

Lo and behold, it's the Pacers that come out on top.

Offensive basketball is evolving, and teams are becoming increasingly difficult to stop.

Just think about the development of the pick-and-roll if you want an example. It wasn't truly popularized until John Stockton and Karl Malone ran it on what seemed like every play for the Utah Jazz during the 1990s, and the league didn't fully adopt it as the play du jour until the 2000s.

Now we see more sophisticated screen-based offenses, like the ones run by the San Antonio Spurs and Miami Heat.

Offense evolves, then the defense has to catch up with it, and that's what makes these current Pacers so impressive. They're ahead of the curve.

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Another way of looking at Indiana's dominance in 2013-14 is analyzing how far they are ahead of the pack. As stated earlier, the Pacers are allowing 4.6 fewer points per 100 possessions than the No. 2 defense in the Association.

In 2003-04, the Pistons only trailed San Antonio by 1.3, and there were six teams in double digits. In 1998-99, San Antonio was only ahead of the second-place Hawks by 2.1 points per 100 possessions, and eight teams were below 100 (which is the limit of the 4.6-point range).

Basically, the other three leading candidates played during tremendous defensive seasons, which devalues the nature of their efforts. You can't say the same for the Pacers.

Although it's still early in the season, Indiana currently boasts the best defense in NBA history. That's not a hyperbolic statement, but rather one steeped in fact and statistical evidence. And scarily enough, the Pacers might get even better, assuming they can stave off the more difficult part of their schedule.

Danny Granger's return gives the bench—which, according to HoopsStats.com, ranks No. 15 in defensive efficiency—a boost and should allow Vogel's squad to maintain more of its defensive prowess when the starters need a rest.

Defense may not be as glamorous as offense. You might not enjoy watching fronts, contested shots and good pick-and-roll hedging as much as highlight-reel dunks, flashy passes and drilled three-pointers.

But enjoy this.

The Pacers are giving you the chance to watch defense played more effectively than ever before.

Note: All stats, unless otherwise indicated, come from Basketball-Reference and are current as of Jan. 9.