Complex sentence: Compared to a full back (full twisting back somersault), a double full is a more advanced move not often seen in high grade routines because it has only 360 ° of somersault rotation.
Split into simpler sentences: Compared to a full back (full twisting back somersault), a double full is a more advanced move. It's not often seen in high-grade routines because it has only 360 ° of somersault rotation.