Complex sentence: Jack Blackburn was a professional rugby league footballer who played in the 1930s, 1940s, and 1950s, playing at club level for Featherstone Rovers (Heritage № 180), as a, i.e. number 2 or 5.
Split into simpler sentences: Jack Blackburn was a professional rugby league footballer who played in the 1930s, 1940s, and 1950s. He played at club level for Featherstone Rovers (Heritage № 180), as a, i.e. number 2 or 5.