Complex sentence: David "Dai" John was a Welsh professional rugby league footballer who played in the 1910s, playing at representative level for Wales, and at club level for Salford, as a, i.e. number 1.
Split into simpler sentences: David "Dai" John was a Welsh professional rugby league footballer who played in the 1910s. He played at representative level for Wales, and at club level for Salford, as a, i.e. number 1.