In a nutshell, I've always believed the more a buck is pressured the less sign he will leave. This pertains mainly to big bucks during their travels.
As far as right by their beds, I think a lot has to do with the type of trees in the beds close proximity.
Example: Hardwood ridge with a bed on a finger with maybe an old windfall right there. Could be very little good rubbing trees close by. Could be a 5 yo bedding there regularly just no desirable trees close by??
I see this when I hunt SE Mn a lot. Makes it tough to determine buck's size. You have to rely on tracks which is also tough in a heavy leaf covered area with hard ground
Where I live, in eastern central Wi. we have a good amount of swamp mixed in with our hardwoods. If a big buck is bedding in cattail/ tag alder area like we have, there will be rubs 80% of the time on those tags leading into his bed or right in it. Especially if its a small, deer sized hump surrounded by water and cattails. They just can't seem to resist rubbing on those tags.
I'm not so concerned about rub size, cause tags normally are 1.5 - 2" max. but I closely look at any ticking of tines or main beam ends that may be only leaving a slight mark on surrounding tag stems. Some of these tags you will see years of old rub scars on, which obviously is a good sign. I really like the bed if it is very secluded and singular meaning only room for one buck.
On a side note on big buck sign, if we're talking big rubs, In my area those big, impressive,4-8" tree, rubs almost always only show up within a few days of our gun opener. (Saturday before thanksgiving) for some reason. Any one else see this?
I always thought this might be some big buck from out of the area.?? Then again it, it's probably a big buck that was right under my nose all bow season and he , in his own way is kinda just flipping me off!!