Strong runs usually move through the same three layers: an opener that keeps you alive, a scaling engine that makes the run grow, and a late-game shell that converts that growth into real score.
Many runs die because players buy endgame ideas before they have a stable opener, or they cling to an opener too long and never transition into a real scoring shell.
If the answer is weak, do not buy a flashy late-game piece and pretend the run is solved.
Look for the part of the build that improves with time, shop cycles, or copy effects. Without that, your ceiling is fake.
Know whether you are moving toward a flush shell, straight shell, steel-kings shell, high-card scaling shell, or another real archetype.