Between the first Carnera bout and the second one, Sharkey had one fight. Against Schmeling in whihc he won the crown. Sharkey certainly looked better in the first bout agianst Max than he did the second one, but I think you can make a solid argument, as many have, that the decision agianst Max was not a "we wuz robbed" moment.
Did Carnera improve? What is the evidence he did? Some shady set up fights? Losses to Gains and Poreda? The Ko over Schaaf who had no right to be in the ring?
Frazier between the first and second Quarry bouts had been worn down in a win over ALi that hospitalized him. Destroyed by Foreman and decisioned cleanly by Ali.
Quarry Who lost to Chuvalo and Ali twice inbetween Frazier bouts, was actually on a very impressive win streak that included Wins over Ron Lyle and Earnie Shavers. Quarry's stock was rising while Frazier's was certainly nothing like it was in the first fight.
Carnera's competency was openly questioned by several writers and experts of the time.
That the Chicago Tribune stated that Primo was better than he was two years ago...Where is the evidence of that?