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ctxprobe

confirmedPython · CPUInference & servingJuly 5, 2026

the question

How does retrieval accuracy degrade with context length and where the answer sits?

what came out

On a real 32k-window model, retrieval degrades past ~17k and shows a clean lost-in-the-middle U-shape -- compounding to 0.30 at 30k-middle versus 0.90 at the start. Length and burial stack.

method & receipts

  • Result: confirmed
  • Reproducible one script re-runs the whole thing from scratch.
  • Machine-readable claims every reported number, in a checkable file.
  • Tested — a correctness/benchmark suite ships alongside the code.

→ read the code and re-run it

github.com/v-code01/ctxprobe