You'd need...
-Incredible health from players who haven't remained healthy on the average, and those who have.
-The Sox to hit the free agency market extremely hard AND for those players all to have historical or better than historical seasons
-Huge growth from all of the core players such as Moncada, Giolito, Lopez, Anderson, etc
-Big years out of the kids in the pen from at least 4 or 5 of them, including being able to slot a 90% conversion closer and key set up men.
-Instant contributions from Eloy and any other rookies called up.
-The Indians do not sell off, or do not sell very many core pieces at all
-No one else emerges from the pack with a miracle year.
We are talking about a 3rd standard deviation scenario here, maybe more. Again, I am pretty comfortable of saying 0 chance that the White Sox are a playoff team in 2019.