Nick Diaz vs. BJ Penn has been the main attraction at UFC 137 since it was announced, even if it has only recently been made the actual main event. Carlos Condit was only awarded his title shot by default when the UFC found itself with an unexpected hole at the top of the card.
Condit vs. St Pierre was never going to capture the imagination of fans in the same way that Diaz vs. St Pierre had. The natural born killer's UFC record is solid with four wins out of five and consecutive knockout of the night awards, but he has yet to achieve the kind of superstar status, which really gives momentum to title ambitions.
The UFC had presumably scheduled his fight with Penn on the same card as St Pierre's scrap with Diaz on the basis that, should he win, Condit could generate a few headlines by demanding a title shot in his victorious post fight interview.
Instead, they were forced to fast track him to a title shot after downgrading Diaz as punishment for a mysterious press conference no-show. With the other welterweight contenders tied up by commitments to future cards, shuffling fighters between the co-main event and the headlining fight was simply the only practical solution.
Diaz vs. St Pierre was a huge fight and, assuming the prospective challenger can get past Penn at UFC 137, it still could be. Diaz currently owns a Strikeforce welterweight belt and seeing champions from two different promotions meet is always exciting for the fans.
There is much more to Diaz's appeal than that. Condit is also still the WEC lightweight champion but he cannot compete with the bad boy image of the unpredictable and enigmatic "Stockton Bad Boy."
Diaz is visibly uncomfortable when a microphone is stuck into his mouth and seems to struggle to string a sentence together in post fight interviews, but that only adds to his allure.
He is not a picture perfect poster boy like St Pierre who will always turn up on time to issue standardized soundbites. Diaz could say and do absolutely anything at any time, and from fighting in the hospital to failing to fulfill media commitments, he is far from your average polished and presentable UFC fighter.
This makes a Diaz fight a much more exciting occasion for the fans than a Condit fight ever could be. It is not just his personality which is unpredictable though, absolutely anything can happen once the Strikeforce lightweight champion steps inside the cage.
At one stage he lost three straight fights by decision in the UFC, his career seemed to be in decline and there was nothing to indicate he would one day become a credible challenger for the welterweight crown. Since then, Diaz has gone on a tear winning 15 out of 16 fights (the gogoplata on Takanori Gomi might read "no contest" on his record but there is no disputing that Diaz won that fight).
The only loss, to KJ Noons, was subsequently avenged and Diaz has consistently beaten elite level opposition like Gomi, Frank Shamrock, Paul Daley and Gleison Tibau. Whether by TKO or submission, he finishes almost every one of his fights, something which St Pierre has been subject to severe criticism for his recent inability to do.
The UFC welterweight division badly needs Nick Diaz because it has become a slightly stagnant place where credible title challengers seem to come and go all too quickly. If he can defeat Penn, matchmakers will be desperate to see him face St Pierre and will want to get Condit's title shot out the way ASAP, or perhaps dispense with it altogether.
If, on the other hand, Penn emerges victorious from the UFC 137 main event, it is unlikely to alter the welterweight landscape significantly. Having lost to the reigning lightweight champion twice and failed to beat St Pierre on two separate occasions, it would be extremely difficult to promote Penn as a credible title challenger at 170 lbs again.
He is in the same no man's land as fellow former champion Rich Franklin, still a welcome addition to any card but unlikely to ever be given another shot at a title. If Diaz could win, and particularly if he can beat Penn emphatically, a title fight between him and St Pierre would suddenly become even more significant.
Condit could of course beat St Pierre and blow the entire welterweight division wide open but you wouldn't bet on it. Jake Ellenberger is another fighter rising up the rankings, but the Canadian champ has seen so many contenders come and go that fans could be forgiven for thinking that neither Ellenberger nor Condit will be any different.
Diaz is different. He brings something to the table which no other fighter on the UFC roster currently can and has boxing and BJJ skills as good as just about anyone in the division. For 170 lbs to become an interesting place again it is absolutely imperative that he beats BJ Penn on Oct. 29.