Harry K writes:

The special, pre-made ones, cost more and may look better but save you
the labor of cutting regular shingles in thirds, not that it is much
of a job.

If you have plain single-thickness three-tab shingles, you can easily
cut them into pieces suitable for the ridge line.

On the other hand, if you have the fancier "architectural" shingles,
they are two layers thick in some places to give a look that is more
like a real wood shingle roof. They'll be harder to cut in thirds, and
may look weird when rotated 90 degrees (so the water flow is "sideways"
relative to the original shingle).

The special ridge shingles are precut, and designed to look thicker than
they really are.

Dave