Why do you think that Kostya Tszyu breath with the mouth on latter rounds?

This is easy. It has to be the pressure. Actually Tszyu was breathing hard very early in the fight. The fast pace and the constant of Hatton laying his body on Tszyu and out muscling him is what wore him down. All of those other things are factors but this is the main one Do you think that in USA (or with an american referee) things like laying his body aren't allowed?

pressure too much and those huge body bombs dont help your stamina either ;p He is getting old. Its like saying Tyson is the same fighter now as he was when he was 18. Big difference. Age. Just like DLH, Trinidad, Chavez, Leonard, Duran, Hearns etc.. Need more? All aging champions with great legacys going out in a bad way. Its boxing. I thought Tszyu was smarter than this!

This is easy. It has to be the pressure. Actually Tszyu was breathing hard very early in the fight. The fast pace and the constant of Hatton laying his body on Tszyu and out muscling him is what wore him down. All of those other things are factors but this is the main one

pressure too much and those huge body bombs dont help your stamina either ;p