UFC Welterweight Fighters
Unlike the relatively shallow talent pool at middleweight, MMA's welterweight division has always been deep with top level competitors. Officially the welterweight division has an upper limit of 170 pounds, with the minimum being just over the lightweight limit of 155 pounds. Prior to May 2001 the UFC referred to the welterweight class as the lightweight division.
The current UFC welterweight champion, Georges St. Pierre, is considered by many to be the 'pound for pound' best fighter in the sport. He receives some criticism for a cautious style by which he 'controls' fights with his superior wrestling and conditioning rather than trying to finish them by submission or knockout. That notwithstanding, he's been one of the UFC's most long reigning and dominant champions—St. Pierre has held the title on two occasions for a total reign of more than 1300 days. In his current reign as champion, 'GSP' has held the belt for nearly 1200 days. St. Pierre has defended the title against Jon Fitch, BJ Penn, Thiago Alves, Dan Hardy, Josh Koscheck and Jake Shields.
St. Pierre's first title reign ended abruptly when he was caught by a 'lucky punch' from heavy underdog Matt Serra, who took the title and held it for just over a year. Serra never defended the belt due to injury, and in his next fight after winning the title he lost an 'interim title' fight to St. Pierre.
The next title defense for St. Pierre will be against another 'pound for pound' best fighter in Nick Diaz. The contrast between the personalities of the two men couldn't be more pronounced—the refined, French Canadian St. Pierre versus the trash talking Diaz who hails from the tough streets of Compton, California. That notwithstanding, Diaz is a seriously talented fighter who excels both at standup (he's had several professional boxing matches) and on the ground where he's one of a handful of BJJ blackbelts awarded by Caesar Gracie. He's also extremely tough and has great cardio and conditioning and will represent the most dangerous fight of St. Pierre's reign.
Prior to St. Pierre's current run with the title the most dominating middleweight champion had been Matt Hughes. Hughes used his power and wrestling skill to control the UFC middleweight belt for over 1500 days in two separate reigns. In his first run as champion, Hughes defended against Hayato Sakurai, Carlos Newton, Gil Castillo, Sean Sherk and Frank Trigg. In his second reign, he defended the title against Frank Trigg and BJ Penn before losing to St. Pierre.
The first UFC welterweight champion (back when it was known as the lightweight division) was Pat Militech, who held the belt for 931 days back when the UFC events were still numbered in single digits. Militech defended his title against Jorge Patino, Andre Pederneiras, John Alessio and Kenichi Yamamoto. He eventually was defeated in 2001 by Carlos Newton.