Choosing an LLM and AI stack

Stage 2 · Lesson 3 of 6

Why multi-step tasks punish small errors

Reasoning quality: when a bigger model pays off

In a task with many steps, small error rates multiply. If a model gets each step right 95% of the time, a 10-step task succeeds only about 60% of the time (0.95 to the power of 10). At 99% per step, it is about 90%.

This is why agents, long data pipelines and multi-file coding feel much harder than single questions, and why the bigger or more reasoning-heavy model often pays off there even when it looks expensive. For one-shot tasks such as tagging a message, the cheaper model's small error rate stays small.

Before choosing, count the steps in your task and ask what one wrong step does to the final result.

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