The Compound Failure Problem

Why "almost reliable" isn't reliable at all

0.95²⁰ = 0.358 — long autonomy is a coin flip dressed as a plan.

Per-Step Accuracy 95.0%

Number of Steps 20

35.8%

chance of full success after 20 steps at 95.0% per-step accuracy

Expected failures per 100 runs: 64

At 95% accuracy, a 20-step task succeeds only 35.8% of the time. One in three. Would you board that flight?

At 99% accuracy, a 100-step task succeeds only 36.6% of the time. Even "near-perfect" fails at scale.

At 99.9%, you need fewer than 70 steps to drop below 93%. No pipeline is immune.

At 90% accuracy, 10 steps gives you 34.9%. Most real-world agent workflows exceed 10 steps.

This is why multi-step AI verification catches errors humans miss. See how →