Likewise, 2% of otherwise-entirely-ordinary bleggs contain palladium, but you have no way of knowing this without taking them to the sorting scanner (which is finicky to start up and takes a minute to run): their metal content is of great practical interest, but seems like a rare, unpredictable fluke, unrelated to any other feature that you might hope to use to distinguish a new category of sortable object.
Likewise, 2% of otherwise-entirely-ordinary bleggs contain palladium, but you have no way of knowing this without taking them to the sorting scanner (which is finicky to start up and takes a minute to run): their metal content is of great practical interest, but seems like a rare, unpredictable fluke, unrelated to any other feature that you might hope to use to distinguish a new category of sortable object.