This article breaks down the gap between your prompts (the map) and the real codebase (the territory) into four types of unknowns and shows how to uncover them. It offers concrete prompting patterns—blindspot passes, brainstorms, interviews, references, and implementation plans—to surface issues before, during, and after coding with Claude Fable 5.

• The gap between your prompt and the actual codebase can be sorted into four unknown types—known knowns, known unknowns, unknown knowns, and unknown unknowns—and naming them helps catch bad guesses before Claude runs with them.
• A "blind spot pass" (asking Claude to list unknown unknowns given your background/project) surfaces gaps you'd never think to mention.
• Having Claude generate multiple HTML mock-ups or fire off one-question-at-a-time interviews forces design and spec assumptions into the open early, before they become costly rework.
• When you can't articulate what you want, pointing Claude at existing reference code (e.g., a Rust backoff crate) to reimplement its semantics is more effective than trying to describe it from scratch.