Rocky Marciano was a great champion who fought a lot of tomato cans in a weak era. He was a fantastic slugger who could apply the pressure and break his opponents down by coming forward with power punches, but the idea that he is the greatest heavyweight in history? Come on. That opinion is either the result of bias or ignorance. I would rate Ali, Tyson, Lewis, Louis, Holmes and Holyfield above Marciano. All of their resumes are more impressive and they have better boxing skills overall. Marciano to me is more on the level of a Moorer, Norton or Klitschko.