IIRC, last year we had (much) more injuries than this year. We set some kind of record with last year's injures. Diego with 33, Chiellini with 32 and Amauri with 30 serie A appearances were the only players last year who didn't miss at least 10 serie A matches. That's important when one makes a comparison between last season and this season.
Another important fact are the episodes in Europe. Last year we played in a much bigger, better and certainly more important tournament. We played in CL where there were no calculations and where players were giving 100%. That still wasn't enough and with only 8 pts won we were eliminated, but the energy wasted in CL surely had its influence in our serie A performances until December. This year we calculated in EL, which was obvious. We surely weren't good, but we also didn't give our best, not the players and not the coach who often rotated the squad, preserving energy for serie A. We didn't qualify and we were eliminated after the 5th round in November. We surely had advantage in serie A this year compared to last year when we also played important and very tough CL matches.
Also, this time last year we were in EL and we already eliminated Ajax, having Fulham to face later on. This year we didn't have EL matches in February and we won't have them in March. We can fully concentrate on serie A.
Yet, the results are the same as last year.