UFC 140 fight card: Jon Jones vs. Lyoto Machida, eras (not just a world title) on the line

Mistakes happen.

Ultimate Fighting Championship (UFC) color commentator Joe Rogan prematurely (and incorrectly) christened the beginning of the "Machida Era" moments after Lyoto Machida destroyed then-light heavyweight champion Rashad Evans at UFC 98 back in 2009.

Who could blame him, really, "The Dragon" was undefeated (15-0) at the time and none of his opponents seemingly were able to put up much of a fight. Mauricio Rua changed all that in short order, exposing a chink in the Brazilian's armor in his next fight and then completely exploiting it in their immediate rematch seven months later at at UFC 113 with a vicious knockout victory.

Machida hasn't been the same fighter since.

Meanwhile, on the other side of town, Jon Jones impressively climbed the 205-pound contender ranks and ultimately secured the top spot with one-sided beatdown of "Shogun" earlier this year. He's already defended his light heavyweight belt, which is no small task, considering Quinton Jackson -- the man he defeated little more than two months ago -- has been the only other man to do it in the past five years.

With another former champion teed up to take out, this time at UFC 140 from the Air Canada Center in Toronto, Ontario, Canada, later tonight (Dec. 10, 2011), "Bones" is on the cusp of doing something special:

Demonstrably declaring the start of his very own "Jones Era."

Jones has been absolutely dominant, finishing six of his last seven opponent inside the Octagon with a sinister blend of (technical) knockouts and submissions. And he's been able to do it, seemingly, without getting touched ... certainly not hurt. In fact, no one has ever wobbled the 6'4" young phenom, who is just 24 years old.

It wasn't too long ago, however, where guys like Rogan, as well as an entire chorus of impressed fans, were saying the same things about Machida. He was an elusive enigma, a fighter that appeared flawless and was able to turn in seemingly effortless winning performances.

Sure, he didn't have the same finishing prowess that Jones possesses, but at the time, we didn't know any better,

When Jones and Machida touch gloves in the UFC 140 main event, it's going to be a test of strong wills and styles -- Jones the calculated and dynamic aggressor, Machida the careful and economic counter striker. On paper, it's terribly difficult to predict an outcome because both fighters are so unpredictable in their very own unique ways.

One fighter will look to usher in his era, while the other will look to reclaim his. Both will need to be mistake-free to make that happen.