Maintained health of pitching staff, including Miller
Solid contributions from Murton and Cedeno
Dempster repeating his numbers from last season
Lee not falling too far from last years numbers
Aramis staying healthy
Pierre hitting for about .320/.370
Neifi getting no more than 75 AB's all season
IF all of those things happen, I think the Cubs will get themselves into postseason play. They might get there without all of those things, but that would take some help from the other teams.
Also, IF Dusty got fired preseason, the team would get about 10 wins better and might be good enough to win the division.