Tires: Two new tire in front of car, rotating tires, operative word

Question
About the theory that if we put two new tires in front of car and two worn ones in back, it will hydroplane in the back and get car out of control. Will this apply to rotating tires front/back?

Answer
Yes, it does.  But the operative word is "difference".

It has been found if the difference is only 2/32nds of an inch,then you can treat the tires as though they are the same depth.

But,of course, the best situation is to avoid this problem completely by rotating regularly.