Complex sentence: ASU was one of only two undefeated Division I football teams that year and one of only four institutions to have gone undefeated and not win a National Championship at the Division I-A level.
Split into simpler sentences: ASU was one of only two undefeated Division I football teams that year. They can also lay claim to being one of only four institutions to have gone undefeated and not win a National Championship at the Division I-A level.