My solid doors have three hinges. On some of them I need to use hinge pin stops.
On which hinge(s) should doorstops be installed?
I do not know if there is a "should".
I have always seen them on the top hinge, probably because it does not require bending over to install.
If you have a middle hinge that may be better as there will be less flexing of the door.
You have solid doors but I have seen them punch holes in hollow core doors. I avoid them if i can, they can cause stress on doors, trim and hinges- loosening/stripping hinge screws. I prefer baseboard or even floor mounted stops.
I placed mine on the top hinge to avoid any fingers getting pinched.
I've always installed them on the top hinge simply because it's out of the way. When using the middle or bottom hinges, the stop inevitably gets caught on shirttails or pant legs. Also, any marks they make on the door or wall are up high and less visible. Small children are also less likely to play with them and inadvertently adjust the stop depth to something that no longer prevents damage.
Consider the wall as much as you do the door, however. What will the stop be coming into contact with? Some people select a hinge such that the stop will rest against a solid piece of trim/molding instead of against drywall, to reduce the likelihood of wall damage. For example, the bottom hinge might be better if your wall has drywall on the top half and wainscoting on the bottom. Similarly, the middle hinge may be wholly inappropriate in a room with a chair rail if the hinge stop and rail end up at the same height. The stop itself should be equally effective on any hinge, just select whichever one fits your environment the best.
A possible alternative (since I agree that hinge stops tend to puncture walls) would be to put a self-closing armature on the top of the door, as those will limit how far the door can open.
Something like this, for example, from Lowe's .
Various observations and strategies offered by others are well taken. My primary use for hinge stops is with bathroom doors and tile walls on my rental apartments. If there's a middle hinge, I think placement there works, but with two-hinge doors, I like both top and bottom stops to minimize flexing.