Complex sentence: Alan Horsfall (birth unknown--June 2007) was a professional rugby league footballer who played in the 1940s, and 1950s, playing at club level for Leeds, and Castleford, as a, i.e. number 8 or 10, during the era of contested scrums.
Split into simpler sentences: Alan Horsfall (birth unknown--June 2007) was a professional rugby league footballer who played in the 1940s, and 1950s. He played at club level for Leeds, and Castleford, as a, i.e. number 8 or 10, during the era of contested scrums.