Complex sentence: Aronin never got the chance to compete internationally, outside the Soviet Union, in an individual tournament, and his only international chances came in a team event in 1957, and in a team match against Bulgaria that same year, where he played two games.
Split into simpler sentences: Aronin never got the chance to compete internationally, outside the Soviet Union, in an individual tournament. His only international chances came in a team event in 1957, and in a team match against Bulgaria that same year, where he played two games.