Well for one thing.. Loaiza probably will not have the same success as last season.
Secondly, Colon (no matter what you think of him) is gone and he was not replaced with a pitcher of the same quality. Even with his down year.. he still had quite a few CGs and Ks. No pitcher added to the SP roster has experienced the same success in his past to prove to me that he is a good enough replacement for Colon.
Lastly, the Sox didn't improve in the offseason.. they stayed fairly stagnant.
No improvements, one major SP loss equals...
85 to 87 wins.
Believe me.. if they win more than that I will be the first one to say I was wrong.