His progess as a true championship pro fighter was 100% because of Steward. The only thing Correa provided was a more exciting version of Lennox Lewis that was a sloppy righthand bomb throwing off balance head hunter.
Steward taught him balance, footwork, and most of all, what it takes to fight through adversity when boxing goes out the window. It was the Mercer fight that Lewis made his transition into manhood.
What he said.
Lewis fought measured/patient and less aggressive and dictated with his physical advantages and let it come rather than forcing things. The irony is that Steward wanted him to be more aggressive against Briggs to be a bit more exciting and he got himself wobbled and in trouble in the fight.