Premise: Arthur John Duckworth (born 19 January 1949) is a former Australian rules footballer who played for Fitzroy in the Victorian Football League (VFL), West Perth in the West Australian National Football League (WANFL), and Central District in the South Australian National Football League (SANFL). He is the older brother of former Essendon footballer Billy Duckworth.
Hypothesis: Arthur John Duckworth played in 3 different football leagues