You must have missed all ofthe rumors of GSP's impending retirement, his clear mental decline, and the increasing physical toll caused by his multiple injuries (fighters are never quite the same after ACL tears you know). GSP would have in all likeliness retired regardless of the result at 167. He fought Diaz in a money fight before Hendricks, that is wrong, but Hendricks got his fight in. Again, Anderson wanted to retire after losing ot Weidman the first time, but he clearly wasn't ducking him. The best part is that there is nothing that you can say that proves me wrong. Can you find any quotes of "I don't want to fight JH."
Yeah, I'd say GSP was past his prime. Several injuries (including ACL tears). Struggling with Diaz in a way that would never have happened before, incluidng uncharactersistic struggling for takedowns and gassing.
People picking GSP by domination were wrong, and even I, one of GSP's biggest fans expected a close decision. People were caught up in the aura of GSP's invincibility, which, frankly, when observed under a microscope didn't quite hold up. Beyond that, Hendricks had not impressed in some of his other fights and had been pissing a lot of people off. People who were suggesting another 50-45 were, in all honesty, lazy, and not interested in giving the fight an actual analysis. Hendricks, for his part, had showed up looking much better than even I had expected (much more diverse striking arsenal than expected, better TDD than expected, more gas than I had though etc...). Yes GSP was decidedly past his prime, when you have multiple ACL tears and have been fighting hte best of the best in your division for 7 years, you can't be expected to be at your best, especially when you have a training regiment as disciplined and physically taxing as GSPs.
GSP and Anderson are very comparable. You like to forget that people had been claiming that Anderson was like fine wine, only getting better with age; I had even heard wispers of comparison to Roberto Duran. Certainly, he had looked excellent against Bonnar, Chael, and Okami of late. Beyond that, you're forgetting that Anderson and GSP have different styles: GSP is a wrestler, and thus, his ligaments and tendons (so essential to his game) are the first to go. Anderson for his part, is primarily a striker. And while Strikers typically lose their chins before they lose anything else, Anderson's defensive skill had led few to doubt his chin. Hell, Anderson was even the favorite in the Weidman rematch. Past his prime? Probably, but you'd never know it coming in to the Weidman fight, while anybody that bothered to look at all into GSP's past few fights could tell that there was some evidence of decline.
It's been a long time RedHawks, I missed schooling you