Lost in the middle confirmed in practice: context ordering matters as much as inclusion

ClickOk5811 · reddit · 2026-09-12

A Reddit user hit a case where a detail buried in the middle of a long context window (between two irrelevant sections) was missed by the model, while the same detail near the start or end was reliably retrieved — matching the documented "lost in the middle" U-shape: retrieval is strong at window edges, weak in the middle, and bigger context windows don't flatten the curve.

Key practical takeaway: context ordering matters as much as context inclusion. A load-bearing fact's position in the prompt does real work. Simply restructuring so the critical piece sits at the window edges fixed the retrieval failure without changing content. The post asks whether this curve holds consistently across current long-context models.

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