sausage cue card

Sausages prefer not to move. If a sausage is on two different things and they are moving differently it will stick with the one that is moving the least.

Staying still beats Moving
Moving beats Rolling

Still beats rotating (on top of your head)

If a sausage is on top of your fork but not you as you rotate, the fork does not try to move the sausage, and therefore counts as still friction.