D. Mandel/Sherdog.com
-- Matt Gale
Jordan Breen, FightFinder czar: I can't say it's entirely an overreaction to the losses. After all, Nate Diaz had mentioned in the past he thought 170 pounds was in his future, and Diego Sanchez had made references to preferring his welterweight diet over his lightweight menu.
However, I don't think the moves are for the better. You're quite right in pointing out that Sanchez's lone loss as a lightweight came to the best lightweight in the world, who very well may be the second-best welterweight in the world. His failures against Penn were not linked to anything physical, but rather the fact that Penn is leagues beyond Sanchez as a boxer, and Sanchez's wrestling was nowhere near good enough to create the sort of scrambles in which he usually thrives. Sanchez just isn't as good as Penn, and it was an easy style match-up for "The Prodigy" to boot.
Sanchez will still be competitive as a welterweight and will still likely earn himself top-10 status. However, the fighters at the top of the weight class continue to get better, and it is still a division full of grappling-savvy wrestlers who can recreate his experience in the Jon Fitch fight. More than that, if Penn does eventually move up to 170 pounds, the title situation is a free-for-all, and Sanchez would have been right in that mix.
As for Diaz, he is a young and developing fighter who lost a couple of close, competitive fights because of his technical warts. Despite his length and toughness, he is incredibly hittable, and worse, he doesn't move his feet. The Clay Guida fight is a great example of the necessity of footwork, as Diaz stood completely still while Guida charged at him, trying to aim at Guida's rapidly oncoming face. These are major technical issues that need to resolved, as they transcend weight. Diaz will be no more able to defend every takedown with a kimura/outer trip at welterweight than he was at lightweight, and probably less so given bigger, stronger wrestlers at 170.
Whether a fighter is going up or down the scale, there are always issues more important than the weight itself. Chiefly, are the shortcomings in your game actually related to your size, and does moving to a new weight class give you a stylistic advantage based on the elite fighters in that division? For Sanchez and Diaz, the answer on both fronts is unfortunately no.