Every single place on-line that I can find that describes a slope ratio
defines it as the ratio of drop to horizontal distance (rise-to-run
ratio), and then gives an example of the exact opposite--for example, a
2:1 slope ratio is illustrated by a one foot rise for a two-foot run. Is
it that there was a mistake in one landscaping textbook 50 years ago
that got perpetuated, so that now everyone in the landscaping business
is confused?