Sam Stout announces retirement at 31

Lightweight Sam Stout wrapped up a 12-year MMA career that featured 20 appearances in the UFC. Al Powers for ESPN

Canadian lightweight Sam Stout announced his retirement from professional mixed martial arts on Wednesday, less than two weeks after suffering his third consecutive loss via knockout.

Stout (20-12-1) made the announcement in a statement released to UFC Tonight. The 31-year-old wraps up a 12-year career that included 20 appearances in the UFC, seven shy of the all-time record held by former light heavyweight champion Tito Ortiz.

"It has become clear to me that I am no longer able to compete at the highest level of mixed martial arts," Stout stated. "Competing as a UFC fighter for the last 10 years has been something I will always look back on with great pride.

"I think my best days as a fighter are behind me and it would be a risk to my legacy and my health to continue competing. Therefore, I would like to announce my retirement from the sport of mixed martial arts."

Stout is probably best known for the back-and-forth nature of his bouts. The UFC awarded Stout a fight of the night bonus six times, as well as one knockout of the night bonus for a memorable shot against Yves Edwards at UFC 131 in 2011.

Fighting out of Ontario, Stout alternated wins and losses between 2011 and 2013, before hitting a three-fight skid. In his most recent appearance on Aug. 23, he suffered a knockout against 26-year-old Frankie Perez less than one minute in.

His most notable wins came against Spencer Fisher, Matt Wiman, Joe Lauzon and Edwards. Nine of his 20 wins came via knockout.