Complex sentence: John Riley was a professional rugby league footballer who played in the 1900s, playing at club level for Wakefield Trinity (Heritage № 141), as a forward, during the era of contested scrums.
Split into simpler sentences: John Riley was a professional rugby league footballer who played in the 1900s. He played at club level for Wakefield Trinity (Heritage № 141), as a forward, during the era of contested scrums.