MMA's 10 best pound-for-pound fighters

Mark it down: Thirty-eight months.

That's how long Anderson Silva's reign atop the Sherdog.com pound-for-pound rankings lasted. In October 2007, "The Spider" usurped the throne from Fedor Emelianenko, a result of the Russian's sagging competition and Silva's crushing middleweight dominance, punctuated by his second violent stoppage win over former UFC champion Rich Franklin.

Now, Georges St. Pierre takes the mantle in a similar situation.

It has been a curious 2010 campaign for Silva, who turned in a polarizing performance against Demian Maia in April that made many question his dedication to the sport. In August, while hampered by a rib injury, he pulled out a miraculous and thrilling victory over rival Chael Sonnen in the fifth round of their middleweight classic. But even in victory, the dominance he exhibited over the previous four years was called into question.

The year has been kinder to St. Pierre. Although he, like Silva, is not immune to criticism -- St. Pierre's cautious, tactical approach and four decision wins in his last five outings have drawn considerable rancor -- Canada's MMA hero continues to thrash elite foes with startling efficiency in one of MMA's deepest weight classes. St. Pierre hasn't even been at risk of losing a round in more than three years, since his first fight with Josh Koscheck in August 2007. When they rematched at UFC 124 on Dec. 11, St. Pierre destroyed Koscheck, almost with his jab alone, and perhaps cemented his status as the greatest welterweight ever.

Heading into 2011, the major question isn't whether it's St. Pierre or Silva who ranks No. 1, but simply whether or not we'll ever see them in the Octagon together in a once-in-a-lifetime matchup.