FanHouse Sean Sherk

The lightweight division in mixed martial arts consists of B.J. Penn and everyone else.

We all know that Penn, the UFC champion, has established himself as the top lightweight in the sport. But after Penn, there are about a dozen guys who are practically interchangeable. That list includes UFC fighters like Penn's next opponent (Diego Sanchez), his last opponent (Kenny Florian), and some past and future UFC opponents like Gray Maynard, Frank Edgar and Sean Sherk.

In B.J. Penn's seven fights since returning to the UFC in 2006, he's 4-3. That record doesn't even come close to telling the story of Penn, the most dominant lightweight fighter in MMA history.

PHILADELPHIA -- There are those who think BJ Penn 's mind is still caught up on Georges St. Pierre and "Greasegate," those who think Penn might have trouble finding the motivation to train hard for Kenny Florian, and those who think Penn may be nearing his end of the line as an elite fighter. In the past, Penn would take umbrage with all those characterizations and lash out.

This time, he's going to let his actions speak for him.

In preparation for his UFC 101 lightweight defense, Penn made the ultimate sacrifice, separating himself from his baby daughter. When Penn left Hawaii to move his camp to San Clemente, Calif., his daughter Aeva was just eight months old. Now two months have passed, fully one-quarter of her life that he has given up in order to dedicate himself to his mission.

PHILADELPHIA -- In his home office, Kenny Florian has a marker board that is essentially a timeline of his past, present and future in MMA. The board lists fighters he's beaten who simply get crossed off, others he's scouted as potential opponents and, of course, his next scheduled matchup.

The name of BJ Penn has long had a prime spot on the board, with Florian targeting a matchup with the UFC lightweight champion for over a year. On Saturday night, Florian gets it at UFC 101.

According to the oddsmakers, Florian is an underdog in the matchup, but perhaps no fighter in MMA has improved more in the last three years than he has. When he got his first title opportunity against Sean Sherk in October 2006, he was essentially a part-time fighter who would take large blocks of time off, only to go into intensive training when he was signed to fight. After losing the Sherk bout, he came to the realization that he couldn't become a champion with that type of work ethic.

From his early UFC days as a contestant on The Ultimate Fighter to his road towards his upcoming title challenge against BJ Penn, there's at least one thing you can always describe Kenny Florian as: ever-improving.

"You talk about The Ultimate Fighter Finale four or five years ago, whenever that was, I always say my skills were zero," Florian said Tuesday during a media call for UFC 101.

Less than two weeks away from his UFC lightweight championship match at UFC 101, BJ Penn found himself fielding questions about a disputed text message and his treatment by the media, and was targeted by a crank caller during Tuesday's UFC 101 media conference call.

Still, at the end of it all, Penn claimed he was focused on retaining his title in his first match back from a drubbing at the hands of Georges St. Pierre at UFC 94.

"I'm fighting for the lightweight championship of the world. That's small stuff," he said. "I don't know how I get caught up in small stuff."

The Ultimate Fighting Championship formally announced today that UFC 103 will take place on September 19 in Dallas, and four fights have been set: Mike Swick vs. Martin Kampmann, Efrain Escudero vs. Cole Miller, Josh Koscheck vs. Frank Trigg and Tyson Griffin vs. Hermes Franca.

Notice anything missing?

It was a big weekend for the lightweights in MMA, with Eddie Alvarez winning the Bellator lightweight tournament on Friday night (above) and Diego Sanchez beating Clay Guida by split decision in a fight of the year candidate Saturday at the Ultimate Fighter Finale.

So what's next for Alvarez and Sanchez? Bellator will have to work hard to attract some top-notch lightweights to challenge Alvarez in their second season (I'm hoping they sign Joachim Hansen), while Sanchez thinks he's earned a shot at the UFC lightweight belt (but I think he should fight Gray Maynard first). My list of the Top 10 lightweights in MMA is below.

After a weekend in mixed martial arts that saw big lightweight fights in both the UFC and Dream, it's time to revise our list of the Top 10 lightweights in MMA. Frank Edgar is new on our list after his impressive UFC 98 win over Sean Sherk, while Gesias "JZ Calvan" Cavalcante has dropped off the list after a disappointing loss to Tatsuya Kawajiri at Dream 9. The full Top 10 is below.

How big a surprise was Frank Edgar's victory over Sean Sherk at UFC 98? So big that UFC President Dana White thought it was impossible.