James Harden is the engine of the Brooklyn Nets' unstoppable offense

There is an old saying that defense wins championships, but what if your best defense is an offense that can't be slowed down?

The Brooklyn Nets are certainly testing that theory this postseason, with an offense that left the Boston Celtics dizzy and sent a message to the rest of the league: Keep up if you can.

The Nets averaged 123.4 points per game while dispatching the Celtics in five games, finishing them off with a 123-109 victory on Tuesday. They did so with supreme efficiency, shooting 49.3% from the field, 41.6% from 3-point range and 92% from the free-throw line.

The success has come in large part due to the otherworldly play of the All-Star trio of Kevin Durant, Kyrie Irving and James Harden.

The offense has been so overwhelmingly dominant that Golden State Warriors forward Draymond Green went as far as to say it could be the best the NBA has ever seen.

That's high praise from a man who played alongside Stephen Curry, Klay Thompson and Durant en route to three straight NBA Finals trips.

While each of the Nets' three superstars has had his star turn in this series, it has become clear that Harden is the engine that makes this offense go.

Durant is averaging 32.6 PPG this postseason, and Irving is averaging 24.8 PPG, but Harden's perfect blend of scoring and playmaking for others has led to an offense that is humming in rhythm.

Harden closed the first round with three straight games of at least 10 assists, including a 23-point, 18-assist masterclass in Game 4, in which nine of his assists were on 3-pointers.

He followed that with a monster triple-double in Game 5 to close out the Celtics, a performance that etched his name in the Nets' record books.

The Nets' offense is a well-oiled machine, and that machine runs on the brilliance of Harden, who averaged 27.8 PPG and 10.6 APG in the first round.

Next up is a matchup many NBA fans have been anticipating, as the Nets will take on the Milwaukee Bucks.

This series has the potential to be a good one, as the Bucks are built to take on the Nets as well as any team, according to FOX Sports NBA Writer Yaron Weitzman.

The Bucks "will test the Nets in all sorts of new ways," Weitzman wrote. "They might be the only team stocked with three players who can make the Nets’ three scorers sweat. Giannis Antetokounmpo just spent a series blanketing Jimmy Butler and will likely be matched up with Durant. Jrue Holiday is a defensive ace, and maybe, given the combination of his size, strength and quickness, the NBA player most capable of making Harden work. And while Khris Middleton won’t blanket Irving, if he’s your third-best perimeter defender, then you’re in a good place."

If the Bucks are to put up a fight, it is becoming apparent that Harden is the man they'll have to slow down first.

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