Complex sentence: The semifinal games were the Rose Bowl and the Sugar Bowl, both were played on New Year's Day, as part of a yearly rotation of three pairs of six bowls, commonly referred to as the CFP New Year's Six bowl games.
Split into simpler sentences: The semifinal games were the Rose Bowl and the Sugar Bowl. Both were played on New Year's Day, as part of a yearly rotation of three pairs of six bowls, commonly referred to as the CFP New Year's Six bowl games.