WR To Slot?
 

Does anyone know, both in real life and in game, what the purpose of moving the WR to slot is?

IRL it can be used to get receivers in the middle quicker, or for the slot receiver to run a route in conjunction with the SE, or to overload a zone, or for probably a number of other positional reasons.

In the game? No idea.

Slot receivers run different routes (see manual playcalling).
Slot receivers may be covered by different players - like LB/S in a base defense.

Also, they are able to get off the block/bump & run better because the coverage is not on them right at the line of scrimmage.

After simming a few games, I've noted that they seem to be more pass-oriented versions of the formations. I don;t have a set of empirical data; I'll try to keep track of that while I run through the MP league I'm in.