He lost to Frankie twice, the first fight was close but most people thought he won, the second fight he got crushed. He was in his prime, but he just didn't match up well with Edgar, who was too fast and his combination of speed, solid boxing, wrestling, movement, and cardio was something Penn didn't deal with well. Went back to WW and dispatched of an old Hughes easily. Had a draw with Jon Fitch who had only lost once in the last 9 years, only to GSP of all people, great performance. Lost to Nick Diaz but actually took a round off of him, Diaz is another bad matchup, iron chined boxer who never stops moving forward. Then he loses to Rory, who he never had a shot against, Rory was hitting his prime and was a massive WW, probably around 200lbs and extremely well rounded. He was probably in or around his prime for those fights. The move to FW probably fucked his body up pretty bad, by the time he went back to LW it was too late