Complex sentence: He scored a total of 11 points out of 34, beating the winner of the tournament Wilhelm Steinitz who at the time had not lost a game for 9 year prior to this tournament and was the unofficial world champion.
Split into simpler sentences: He scored a total of 11 points out of 34, beating the winner of the tournament Wilhelm Steinitz. At the time, Steinitz had not lost a game for 9 year prior to this tournament and was the unofficial world champion.