Complex sentence: Bill Renton was a professional rugby league footballer who played in the 1920s, playing at representative level for Yorkshire, and at club level for Castleford, as a, i.e. number 8 or 10.
Split into simpler sentences: Bill Renton was a professional rugby league footballer who played in the 1920s. He played at representative level for Yorkshire, and at club level for Castleford, as a, i.e. number 8 or 10.