Undisputed champion recognised a different champion. The disputes were usually short-lived as a lucrative fight would be organised between the rival champions. The longest split was ten years, of the middleweight title, between Mickey Walker's move up to heavyweight in 1931 and NBA champion Tony Zale's defeat of NYSAC contender Georgie Abrams in 1941. An early use of "undisputed" appears in a "New York Times" preview of the 1941 fight. The growing popularity of boxing outside of the USA led to creation of various boxing organizations, each strengthening their influence (most notably BBBofC) and having their own champion. This resulted in a
Undisputed champion most wins in WBO Heavyweight title fights with 8. By 2001, the WBA was giving the same recognition to WBO champions as to WBA, WBC and IBF champions. In 2004, the WBC began naming WBO champions on its ranking listings. The IBF did not recognise the WBO in May 2006, but was doing so by February 2007. Conversely, the WBO explicitly recognises the other three sanctioning bodies. Some sources consider the WBO title necessary for an undisputed champion. Others continue to consider it sufficient to hold the WBA, WBC, and IBF titles. Other bodies such as the IBO, IBU, and