Complex sentence: Boca Juniors de Cali was one of the most important teams of its time, it had been in second place at the end of the seasons of 1951 y 1952, in both chances behind the team Millonarios of Bogotá.
Split into simpler sentences: Boca Juniors de Cali was one of the most important teams of its time. It had been in second place at the end of seasons 1951 and 1952, in both cases behind the team Millonarios of Bogotá.