Or asked another way -
How much easier is it (typically) for a player to hit touch AC rather than regular AC?
This is a supporting question for:
I'm looking for the average difference between creature AC and touch AC at each Challenge Rating level to try and support another question I am trying to get answered.
In this case the question is does targeting touch AC for grapple attempts give an advantage over simply trying to hit the monster with a base attack in the first place. To do that we need to know the average difference between AC and Touch AC at the various levels of play.
I've seen a few questions out there asking for the average AC or saving throws for various monsters at each CR level, but not found one for the average difference between AC and Touch AC.
Is anyone able to generate that data? Or where and how can go about collecting it?