Sergio has a style based on youth. Been in a lot of tough fights, and it has caught up with him. The inactivity at this age is really hurting him.
Unfortunately, when you are the recognized champ at 160, and you repeatedly opt for softer opposition, instead of the real top contenders, you do have something left to prove. He has to prove that he wasn't/isn't a fraud. Barker, Macklin, and Chavez Jr. weren't/aren't better than Golovkin, Ward, or Pirog. I threw Ward in there, because Martinez calls out little Pacman, and Mayweather two weight divisions below him, but he won't even meet Ward at a catchweight, and Ward is only one division above him. Also, Murray should really have a win over Martinez, and if the fight was any place else than Argentina, he would have. Bogus scoring, and a hometown ref, who took away a legit knockdown, when Martinez tasted canvas.
any other time Martinez fought murray he'd have had 2 hands to fight with... Martinez has been poor/injury ridden over the last 2 years, but its very poor form suggesting he might be "a fraud". hes undeniably the legit MW king . 3G has only in the past year or two got a foothold in the US, and it happens to coincide with the twilight of matinez's career, so nothing gets proved there, does it? back to back wins against pavlik and Williams is all you should need to know the guy never was a "fraud"