Potentiometer stick
Also called pot stick · ALPS stick
Most controller sticks measure position with potentiometers: a contact that slides along a resistive track. Wear and dust on the track are the most common cause of stick drift.
In practice
Potentiometers are cheap, precise when new and used in most standard controllers. Their weakness is wear. The contact that slides along the track eventually wears grooves and leaves debris, which makes the reading noisy or offset. That is why drift appears after months or years of use rather than out of the box.
How to check
A worn potentiometer shows as resting drift in the controller test or as jumps when you move the stick slowly. Compressed air around the stick base can push debris aside temporarily. Replacing the stick module is the lasting fix and on most controllers it needs desoldering.