A big reason for the piggyback last year was that they had some very young starters, and also a lot of them. Didn't they open the year with Wooley, Rogers, Gallardo, Hinton, Stanczyk, Parillo, Beresford, Barnes...basically, they had about 8-9 starters and some (like Rogers) struggled to throw strikes. This year the rotation is a bit older, and likely more efficient with their pitches. Plus, they probably only have 5-6 starters.