Uphill means solving
Research, technical investigation, and design decisions are uphill. Progress can be real even if nothing has shipped yet, provided uncertainty is shrinking.
Downhill means executing
Downhill work has an agreed approach. Surprises can still happen, but the team is primarily sequencing and completing known steps.
Avoid false precision
Do not map points to percent complete. Ask whether the team could explain the solution to another person; that is the practical test for the crest.