Mike McCallum used to be underrated but now he is is a bit overrated. Holmes got his due, but he attitude after losing to Spinks in the first fight and losing those 2 fights hurt his legacy. Graham and Kalambay go down similarly. Good fighters and some good wins but losses to Jackson and McCallum and Nunn for Kalambay does not show underrating. I think all those guys were ranked high, but did not have that great big win which would propel them into the elite level. I think most people assume they could have won against the elite guys, so that might be why they are seen as underrated.
underrated right now is Mike Tyson. People rate him more for the Douglas fights and onward than his 1986-1989 fights. The thing I like about Mike is he never made excuses for losses. A class act.
Sammy Mandell is pretty underrated for a lightweight I feel. DIdn't have the best chin of course, but he was a great boxer. He cleaned up old timers Rocky Kansas and Johnny Dundee before beating the likes of Tony Canzoneri, Jimmy McLarnin, Billy Petrolle, Jackie Fields and Sid Terris. Can't name too many lightweights with a better wins resume than that....
Famasito Gomez Art Hafey Simon Brown Hedgemon Lewis Joey Giardello While we are at it, been her for a couple of years or so, and only seen Andre Wards name 3/4 times most, am I right ? keep well.