(Guess who I'd pick in this fight.)
When it comes to multiple belts and talent dilution, boxing still reigns supreme. Ask a boxing fan who the welterweight champion of the world is, and he/she will tell you it's Manny Pacquiao, whom currently holds the WBO belt he took off of Miguel Cotto. A hardcore boxing fan may feel the need to explain that there is also a WBC welterweight title (currently held by Andre Berto), with WBA (Vyacheslav Senchenko) and IBF (Dejan Zavec) belts also in the mix at that weight. At just about every weight, in fact.
Ask a mixed martial arts fan and you'll receive an answer similar in obviousness to Pacquiao - "GSP". Then again, if you ask a hardcore MMA fan (whom, given my experience, will have probably scoffed at you numerous times by this point), you'll probably hear an additional answer - Nick Diaz, Strikeforce's current WW champion, coming off of a successful title defense last night against Cyborg Santos (the husband, not the wife). If this hardcore also happens to be a pothead/209 resident/Diaz fan, you may even leave with the impression that Diaz is the de facto #2 WW in the world and the only man in the division capable of giving GSP a real fight.
This would be quite the mistaken conclusion to draw.
Nick Diaz was the inaugural WEC champion at 170 pounds and came into the UFC as a twenty year old with a 7-2 record. Upon entering the UFC and re-defeating Jeremy Jackson (Diaz having already beaten him a scant two months earlier in another organization), Nick began the longest streak of consistently fighting at one weight class for one organization in his career, making the 170 lb limit for eight consecutive UFC bouts, stretching from September 2003 to April 2006. Nick went 4-4 during this stretch, culminating in a three fight losing streak to Diego Sanchez, Joe Riggs and Sean Sherk that resulted in the termination of his contract.
Nick decided to stay at 170, and was welcomed back into the UFC after a single win for a smaller promotion in his hometown of Stockton. He bested Josh Neer and Gleison Tibau (both of whom subsequently cut to 155) in rapid succession and seemed ready to regroup and get into the title hunt with another win or two. However, Cesar Gracie had yet to be disabused of the notion of starting a new MMA promotion, and Nick stayed loyal to his camp, leaving Zuffa in the interest of participating on the inaugural card of the Gracie Fighting Championship.
Reality made clear in a matter of months that Diaz, nor anyone else, would be fighting Thomas Denny on a GFC card. This quick realization meant that Nick was available to fight Takanori Gomi at Pride 33, where he sunk in the most impressive NC finish I've ever witnessed, hitting a gogoplata on Gomi while violating the prohibition on performance inhibiting plants. From there, Nick went to EXC, beginning a long experiment with different weights, getting cut wide open and not fighting the grapplers that troubled him in the UFC.
This is where Diaz begins to build his "case" as a potential challenger to GSP. After a brief journey down to 155 (quickly remedied by KJ Noons and his sharp knuckles), Diaz began a nine fight winning streak that encompassed his EXC career, a couple of DREAM bouts and his entire Strikeforce career up until today. For one bout, Diaz came in at 169.5 pounds for a fight that was agreed upon at 160. That's 9.5 over for those not paying attention. For another, Diaz met Frank Shamrock - coming off of a loss to Cung Le and holding two wins since the occupation of Baghdad - at a 180 lb catchweight. Immediately after that, Diaz took a 179 lb bout against Scott Smith, who was RNCed out of the UFC by Ed Herman (remember Short Fuse? Tito didn't pick me? That guy) two years prior.
While not fighting Jay Hieron or Joe Riggs (whom, let's remember, is 1-0 against Nick Diaz), Nick found himself in a real live welterweight match-up against Marius Zaromskis for Strikeforce's inaugural strap. Since then, Diaz has fought Mach Sakurai in Japan and defended his belt against KJ Noons (who moved up to 170) and the aforementioned Cyborg.
Now, this is all well and good. Nick's on a solid win streak over some good fighters and is normally fun to watch. However, you many notice something about his post-UFC resume - it's remarkably devoid of good wrestlers/grapplers, the sort of which he had issues with before leaving Zuffa. Of Diaz's last five UFC fights, four of his opponents (against which he went 2-2) eventually went down to lightweight (Diego may be back at 170 for good) and two of them (Neer and Riggs) are no longer with the company. I think it's safe to say that Diaz has not fought a better fighter than Sean Sherk since that loss. It's absolutely safe to say that Sherk was the last solid 170 lb wrestler that Nick fought.
Mayhem Miller? Too big, hasn't beaten anyone and doesn't get a payday because he ran his mouth. Joe Riggs? Does nothing for me - I deserve bigger names. Jay Hieron? Forget that - he lost to GSP in 2004. I can see it now - who the hell is Tyron Woodley? What has he done to deserve a spot opposite me on the billing? I'm not in a position to assign the majority of blame to Strikeforce, Showtime, Cesar or Nick himself - but I can say, with confidence, that Diaz wouldn't be their WW champion unless all of those sides collaborated under the umbrella of making sure Nick doesn't get wrestlefucked for three or five rounds. I haven't seen Diaz against a decent wrestler, let alone a good one, in years. I can't not pick Rick Story or Johnny Hendricks over him in a fight.
Mixed martial arts remains leaps and bounds ahead of its combat sports progenitor in terms of consolidation at the upper echelons of talent. While Strikeforce belts exist, most view them as little more than a trinket, emphasized by Alistair Overeem's "reign" as their HW champion. Overeem has defended the belt once since winning it against Paul Buentello over three years ago, against a Brett Rogers coming off of a loss, and will not be defending the belt again until after the scheduled tournament. His placement in the rankings - and in hypothetical match-ups against other top HWs - is completely and utterly independent of the belt.
Diaz absent the strap is still probably ranked right about where he is today, despite having a single win over a welterweight currently ranked in the USAT/SBN Top 25 (gold star to whomever gets it first in the comments). That doesn't mean we shouldn't pretend that his belt is anything other than it is - a nice gift from Coker and company, lovingly tended to with favorable stylistic match ups.