sparring gym killers that whooped big champions and never shine on the big scene of boxing/ lost in the process?

[franciscojavier]

He has some noteworthy victories as a Pro too don't get me wrong. He just never hit the very, very top. He breathed on it a few times though.

I was a big fan of Andy.

I think it says something about Andy’s quality as a fighter and reputation among the fans that Chávez Jr.’s win over him was the thing that convinced a lot of people to briefly take him seriously, as much as or more than his big 12th round against Martínez.

[apollo creed]

He has some noteworthy victories as a Pro too don't get me wrong. He just never hit the very, very top. He breathed on it a few times though.

I was a big fan of Andy.

I think it says something about Andy’s quality as a fighter and reputation among the fans that Chávez Jr.’s win over him was the thing that convinced a lot of people to briefly take him seriously, as much as or more than his big 12th round against Martínez.

Tbh Chavez Jr had some talent and also good physical qualities to be a top fighter but he lacked of discipline and dedication.