This is a good list, although in relation to 1900-1909, even though he was way past his best, i think that Bob Fitzsimmons was pound for pound quite likely the best. Certainly he had no peers for the 1890 to 1899 decade.
I dont disagree in relation to his heavyweight accomplishments, but i was thinking more on a pound for pound basis. Evander has his dominant reign as cruiser champ (although admittedly it was before 1990), and while he did lose to Bowe in his series and also to Lennox, it is offset by him giving away huge weight and size to both. As a pound for pound fighter i think Evander was probably just ahead of Lennox in the 90s, although i can see arguments for Lewis as well.
1900-1909 -Joe Gans 1910-1919- Sam Langford 1920-1929- Harry Greb 1930-1939- Henry Armstrong 1940-1949- Sugar Ray Robinson 1950-1959- Archie Moore 1960-1969- Muhammad Ali 1970-1979- Roberto Duran 1980-1989- Sugar Ray Leonard 1990-1999- Pernell Whitaker 2000-2009- Manny Pacquiao
That's interesting, why do you say that? Robinson in his peak and beaten only once made this an easy pick for me.
1900-1909 -Joe Gans 1910-1919- Sam Langford 1920-1929- Harry Greb 1930-1939- Henry Armstrong 1940-1949- Sugar Ray Robinson 1950-1959- Archie Moore 1960-1969- Vicente Saldivar 1970-1979- Alexis Arguello 1980-1989- Sugar Ray Leonard 1990-1999- Pernell Whitaker 2000-2009- Manny Pacquiao
He crosses over the 70s and the 80s, I think there is better candidates in each decade that surpass his half of career in that decade.
Napoles' vastly better technical acumen and overall depth of skillset would be the main reason. Like most (all) of Mantequilla's opposition he'd have his offence shut down and end up missing and getting countered. Add in his ability to cut off the ring and Ali's vulnerability to types who are efficient at closing the distance and you have a stylistic near-nightmare. And I'm no Ali hater. Just shows you how weak Heavyweight history is by comparison.