This is a forward roll driven backup variation of Cripple Creek based on Earl Scruggs's playing on the original recording. This rolling backup is best suited for backing up a fiddle. However, if you make sure to control your volume and not play louder than the soloist rolling backup can work great behind a mandolin or guitar.
Check out some of the licks for some vamping options. This chordal style backup is better suited for backing up another banjo player, and really helps fill the gap left when a mandolin player takes a solo. Somebody needs to keep that "chop" going!