who would win and why .

[Dark Lord Al]

I think when it's prime vs prime:

Pavlik beats Roldan UD
Fenech beats Barrera UD
Hagler beats Toney UD
Hearns beats Mosley TKO late rounds
G-Man beats Ketchel KO
Jackson beats Monzon KO
Mayweather beats Pryor SD
McCallum beats Taylor easy UD
Olivares beats PacMan SD
Hearns beats Calzaghe KO middle rounds

Not a million miles of my line of thinking