Complex sentence: No one knows for sure, but legend has it that no one really is sure how NCAA teams are picked for the tournament and NCAA officials pick teams at random, even if the team is ill deserving of a spot.
Split into simpler sentences: No one knows for sure, but legend has it that no one really is sure how NCAA teams are picked for the tournament. Rumor is NCAA officials pick teams at random, even if the team is ill deserving of a spot.