The NBA has changed dramatically in the past 20 years. The 2020-21 season, for example, produced the seven highest offensive ratings in league history. Modern teams continue to sharpen their ability to play more efficient offense than we've ever seen.

As we're looking to identify the best offenses of the past two decades, we'll do so with an eye on offensive prowess relative to the rest of the league at the time. That relativity helps level the playing field a bit.

Yes, today's offenses are better than most of the NBA's top units 15 to 20 years ago. However, some older scoring attacks produced at a higher level than the rest of the league at the time. They deserve praise for being ahead of the offensive efficiency curve.

Or, perhaps more accurately, for paying Steve Nash.

While the order is subjective, the choices are based on various metrics―offensive rating and effective field-goal percentage, among others―compared to the league's season average.

10. 2020-21 Brooklyn Nets

Considering the roster featured three of the best scorers in this generation, it's no surprise the Steve Nash-coached Brooklyn Nets had a brilliant year.

Brooklyn acquired James Harden from the Houston Rockets early in the season, teaming him up with Kevin Durant and Kyrie Irving. Harden averaged 24.6 points and 10.9 assists, while Durant and Irving both scored 26.9 points per game.

As a team, the Nets several broke NBA records—most notably in offensive rating (118.3), effective-field goal percentage (57.5) and true shooting percentage (61.0).

Unfortunately for Brooklyn, injuries stung the roster at the worst moment. Irving and Harden both missed time in the playoffs, and the Nets fell to the eventual-champion Milwaukee Bucks in the second round.

9. 2019-20 Dallas Mavericks

In 2019-20, we enjoyed the full Luka Doncic experience.

Although he captured many headlines as the 2018-19 Rookie of the Year, the versatile guard took the Dallas Mavericks to a new level in his sophomore season. Doncic registered 28.8 points and 8.8 assists per game, and the Mavs surrounded their young superstar with a boatload of long-range shooters.

Tim Hardaway Jr., Seth Curry and Trey Burke all made multiple threes per game while hitting them at a 39.8 percent rate or higher. Three more regulars—Kristaps Porzingis, Dorian Finney-Smith and Maxi Kleber—each shot above 35 percent, too.

Before seven teams surpassed the mark in 2020-21, the Mavericks set an NBA record with a 116.7 offensive rating.

In the postseason, Dallas offered a clear reminder that offense isn't everything. Kawhi Leonard carried the Los Angeles Clippers to 126.7 points per game, eliminating the Mavs in the first round.

8. 2002-03 Dallas Mavericks

During the early 2000s—and you'll see this clearly soon—the Mavericks built an offensive juggernaut.

In 2003-04, they won a league-high 60 games behind the trio of Dirk Nowitzki, Steve Nash and Michael Finley. Nowitzki paced the Mavs at 25.1 points per game ahead of Finley's 19.3, while Nash averaged 17.7 points and 7.3 assists.

Dallas scored an NBA-best 103.0 points per game and ranked third with a 38.1 three-point percentage. Additionally, the 110.7 offensive rating was both 4.8 higher than the second-best offense and 7.1 higher than the league average.

But the season would end just short of the ultimate goal. The rival San Antonio Spurs bounced the Mavs from the playoffs in the Western Conference Finals.

7. 2006-07 Phoenix Suns

The first of two "Seven Seconds or Less" offenses highlighted, the 2006-07 Phoenix Suns helped shape the modern NBA.

Nash expertly facilitated head coach Mike D'Antoni's fast-paced attack with All-Star teammates Amar'e Stoudemire and Shawn Marion, dishing an NBA-high 11.6 assists per game. Overall, the Suns ranked No. 1 in offensive rating (113.9), three-point percentage (39.9), points per game (110.2) and two more major categories.

Phoenix set a then-NBA record in true shooting percentage (59.0) and matched the "Showtime" era 1984-85 Los Angeles Lakers in effective field-goal percentage (55.1).

However, the Suns exited the postseason at the hands of the Spurs—an all-too-familiar result for Phoenix around this time.

6. 2009-10 Phoenix Suns

Three seasons later, Phoenix put together its best offensive year and eliminated the Spurs in the playoffs.

Yes, the 2009-10 campaign did not include D'Antonio and also preceded the dissolution of the Suns' memorable era. But the benefit of hindsight should not detract from Phoenix's year.

Once again, the Suns led the NBA in offensive rating (113.9), three-point percentage (41.2) and points per game (110.2). They also posted a 54.6 eFG% and 58.5 TS%, which both stood as top-six marks in NBA history at the moment.

Most notably, Phoenix outperformed the league average offensive rating by 6.3 points and second-ranked offense by 3.4.

Nash and Stoudemire took the Suns to the Western Conference Finals, where they fell to the Los Angeles Lakers. Stoudemire left for the New York Knicks in the ensuing offseason.

5. 2003-04 Sacramento Kings

This is pretty rough luck for the Sacramento Kings, who aren't even the best offense of the 2003-04 season.

Nevertheless, the Kings assembled a stellar year despite All-Star forward Chris Webber (knee) playing in only 24 games. They leaned on top scorer Peja Stojakovic and an unselfish supporting cast to record an NBA-leading 50.7 eFG% and 55.4 TS%.

Stojakovic scored 24.2 points per game, and the rest of the starting lineup—Vlade Divac, Brad Miller (until Webber returned), Doug Christie and Mike Bibby—all averaged at least 4.3 assists.

While the Mavs tallied an NBA-high 112.1 offensive rating, the Kings checked in close behind. At 110.3, they bested the 2003-04 league average of 102.9 by 7.4 points.

Sacramento lost to Kevin Garnett and the Minnesota Timberwolves in the second round of the playoffs.

4. 2001-02 Dallas Mavericks

Through four NBA seasons, Nash typically held a smaller role. He'd logged 67 starts for Dallas in two years after the Mavs acquired him, but he'd never been a featured player. That changed in 2000-01, and they began to excel in 2001-02.

Nash averaged 17.9 points and 7.7 assists with a sizzling 45.5 three-point clip. Nowitzki landed his first career All-Star nod, and Finley averaged 20-plus points for the fifth straight season.

The trio propelled Dallas to a 112.2 offensive rating, which was 7.7 points higher than the NBA average. Plus, the Mavs paced the NBA in eFG% (50.7) and TS% (55.3). For good measure, they also generated a league-low turnover percentage (11.3).

Sacramento, the No. 1 seed in the Western Conference the year, toppled the Mavs in the second round.

3. 2015-16 Golden State Warriors

Basically the only thing missing from the 2015-16 Golden State Warriors is a title. That's an important void, sure, but the Dubs still had a legendary year.

Stephen Curry won his second successive MVP, and both Draymond Green and Klay Thompson landed All-NBA honors. While setting an NBA record with a 73-9 regular season, the defending champs finished first in several key stats.

Golden State shot a league-high 48.7 percent, leading the NBA both inside (52.8) and beyond (41.6) the arc. The offense poured in 114.9 points per game with a 56.3 eFG% and 59.3 TS%.

Plus, the Warriors obliterated the league average offensive rating of 106.4, ending 8.1 points ahead at 114.5.

LeBron James and Irving propelled the Cleveland Cavaliers to their unforgettable 3-1 comeback in the NBA Finals, ruining Golden State's epic year. But the Warriors won the next two NBA titles.

2. 2004-05 Phoenix Suns

Phoenix drafted Nash in the first round of the 1996 NBA draft. Two years later, the Suns dealt him to Dallas. But after seeing him develop into a superstar, they signed him as a free agent in 2004.

And the re-acquisition sparked the "Seven Seconds or Less" era.

Nash earned his first of back-to-back MVPs in 2004-05, averaging 15.5 points and an NBA-best 11.5 assists. Stoudemire put up 26.0 points per game, while Marion (19.4), Joe Johnson (17.1) and Quentin Richardson (14.9) completed a prolific lineup.

Even as the NBA recorded an average 106.1 offensive rating, the Suns ascended to a plus-8.4 mark at 114.5. Phoenix led the league in eFG% (53.4) and TS% (57.1), too.

Sadly for Phoenix, though, the eventual-champion Spurs eliminated the Suns in the Western Conference Finals.

1. 2003-04 Dallas Mavericks

In the introduction, we noted the importance of relativity. Based solely on shooting metrics, the 2003-04 Mavericks aren't particularly close to the top of a greatest offense list.

Dallas, however, had a relentless attack in a year of defensive strength. The league-average offensive rating of 102.9 was the second-lowest figure since the 1977-78 season, only trailing the strike-shortened NBA campaign (102.2) in 1998-99.

Still, the Mavs registered a 112.1 offensive rating—a jarring plus-9.3 and easily the largest difference since 2000.

Nash—a point guard for six of these 10 offenses and a coach for one more—stirred the unit with 8.8 assists per game. Nowitzki scored 21.8 points per game, while Finley, Nash, Antoine Walker and Antawn Jamison each averaged at least 14.

Dallas notched a league-best 11.1 turnover percentage and grabbed the third-highest rate of offensive rebounds (31.4), which both atoned for a modest 34.8 three-point clip.

Sacramento had the last laugh in 2003-04, finishing behind Dallas in offensive rating but erasing the Mavs in the first round.

Follow Bleacher Report writer David Kenyon on Twitter @Kenyon19_BR.