Complex sentence: Willam "Billy" Thomas is a Welsh professional rugby league footballer who played in the 1930s, playing at representative level for Wales, and at club level for York (captain), as a stand-off/five-eighth, i.e. number 6.
Split into simpler sentences: Willam "Billy" Thomas is a Welsh professional rugby league footballer who played in the 1930s. He played at representative level for Wales, and at club level for York (captain), as a stand-off/five-eighth, i.e. number 6.