Diaz is a talented fighter, and an intriguing personality. He’s nuts in a way that appeals to people. He never gets finished so even when he loses, he somehow proclaims that he didn’t lose. And the fact is, he hasn’t lost in a long time anyway.

But his history has included missing two fights at the last minute, one because even when warned, he couldn’t stop using marijuana, put it on his medical listing as a drug he used when it was illegal for fighters, and the commission wouldn’t allow him to fight.

He blew another fight with Jay Hieron when he no-showed a drug test that he was likely to fail. It wasn’t just no-showing a drug test, but it was no-showing for days on end and telling promoter Scott Coker that he was going, and then taking off.

Then there was the time he missed weight–by nine pounds. He was in the ocean and swallowed salt water and thus wasn’t able to cut weight.

Another time, in the Frank Shamrock fight, even though he usually fights at 170, they made it a 179 catch weight fight, and a few days before, his side asked for it to be raised a few pounds because he wasn’t going to be able to make 179.

And then there was the time against Joe Riggs, where he lost the fight in the cage, and later that night, he saw Riggs in the hospital and attacked him and started a fight there.

And then there were the two most famous brawls in U.S. MMA history, the one with the family of K.J. Noons in Hawaii, and the one where he and his crew, five-on-one, beat up on Mayhem Miller when Miller issued a challenge to Jake Shields. That one cost Strikeforce its CBS contract.

He no-showed the press conference on 9/6 in Toronto. The next day, he promised he would be in Las Vegas. His coach, manager and father figure, Cesar Gracie, was supposed to watch over him and deliver him. But he snuck out the door and left.

—

So UFC 137 was announced as having a double main event, Georges St. Pierre defending the welterweight title against Carlos Condit, and Diaz vs. B.J. Penn, with Penn and St. Pierre switched opponents.

Then all weekend, Diaz started having second thoughts according to people very close to both fighters. At one point he got word to the Penn camp that because of his respect for Penn that neither he nor brother Nate would ever fight Penn.

Penn himself was hopeful of Diaz doing the fight, because he was afraid that if he didn’t, with Jon Fitch on the shelf until December, that he wouldn’t be able to get another fight this year, and felt he needed one more win to get GSP back in the cage.

On either 9/12, apparently he was talked into changing his mind, since not doing the fight would be the worst thing possible for his career at this point. With no independent Strikeforce and basically nowhere you can make money, doing what Dana White would construe as backing out after being handed a break would almost surely spell the end of his UFC tenure.

Diaz was punished for no-showing in a big way, including being taken out of a fight he’s wanted for years and basically his career in UFC was at stake if he wouldn’t have faced Penn, The difference in what he’s going to make fighting Penn in the semifinal with what he would have made against St. Pierre is said to be in the seven figures due to the PPV cut.

He’s also out of the title picture, at least for this year. He’s gone from seven figures, even if he lost, to essentially very slightly more than he would have made had he fought Tyron Woodley in Strikeforce for the welterweight title he vacated to get the St. Pierre fight.