There's the first series to get away...

With that series split - if the Cubs win out their remaining series (21 to go), they end up with 94 wins.

Here's what it will take to get to 94 wins now - they have to...

win 2/3 vs. STL
win 2/3 vs. SF
win 3/4 vs. AZ
win 2/3 vs. PHI
win 2/3 vs. NYM
win 2/3 vs. CIN
win 3/4 vs. STL
win 2/3 vs. HOU
win 2/3 vs. COL
win 2/3 vs. ATL
win 2/3 vs. FLA
win 2/3 vs. LAD
win 2/3 vs. PIT
win 2/3 vs. STL
win 3/4 vs. SF
win 2/3 vs. CIN
win 3/4 vs. STL
win 2/3 vs. MIL
win 2/3 vs. HOU
win 1/2 vs. PIT
win 3/4 vs. HOU

That will equal 46 wins/21 losses, for a final record of 94-68 (a record that probably gets them in).

I've bolded the series that will be challenging for them to win. Every series from this point forward that they fail to win drops their total possible wins by at least one (and 2 if they lose a 4 game series).

There's not a lot of room for error at this point.