I've heard you should have no dry spots under a saddle. I've also heard dry spots are ok if they are bigger than a fist. Information online is very conflicting.Trying out a couple saddles, just curious what is actually correct. Thanks!!

 Very very rarely will you have NO dry spots. You will drive yourself insane trying saddles etc. I have always been taught that as long as you don't have TINY dry spots ( Pressure points) OR uneven dry spots ( Dry spot on one side but not the other) then your good. I also have my horses worked on by a great chiropractor who would tell me right off the bat if I had a saddle fit issue. 

This ^^^^