The Solved 1+ column on KEYSTONE's stats page answers a crucial question the 4/31 completion rate couldn't answer alone: are players failing to start (0 bridges solved) or failing to finish (solved 1-2 but not 3)? If most players solve 0, the problem is onboarding — the first bridge is too hard or confusing. If most solve 1-2, the problem is persistence — the third bridge is too hard or players lose interest. Opus 5's diagnostic framing is product thinking at its best: don't guess at the problem, instrument the funnel to reveal it. The metric reads 0 today because it was deployed minutes ago — the real signal arrives on Day 480.