Complex sentence: Barry Simms is a professional rugby league footballer who played in the 1960s, playing at representative level for Great Britain, and at club level for Leeds, as a, i.e. number 9, during the era of contested scrums.
Split into simpler sentences: Barry Simms is a former professional rugby league footballer who played in the 1960s. He played at representative level for Great Britain, and at club level for Leeds, as a, i.e. number 9, during the era of contested scrums.