Top pound-for-pound boxer Terence Crawford, retires on top with 42-0 record

Terence Crawford, who claimed the title of best pound-for-pound boxer with a convincing victory over Canelo Alvarez in September, announced his retirement on Tuesday.

​ Terence Crawford, who claimed the title of best pound-for-pound boxer with a convincing victory over Canelo Alvarez in September, announced his retirement on Tuesday. Read More Breaking News, Latest News and Videos | CNN