# HEADPASS-X3: Cross-encoder reranker choosing the appended chunks on the HEADPASS path

> Living preprint · as of 2026-10-25 · map node X-164 (experiment) · interim record, not a final result.

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- [X-164] HEADPASS-X3 · Cross-encoder reranker choosing the appended chunks on the HEADPASS path · question: Cross-encoder reranker choosing the appended chunks on the HEADPASS path (X3a reranker-only, X3b X1 + reranker; bge-reranker-v2-m3 over BM25 ∪ dense ∪ top-article candidates, under the X2b token budget) · result: reach 111/109 vs 117; 21.4 s/item. · set 180 self-tests replays + v0.1/v0.2 kit no-harm; 0 judge calls; reranker latency timed, judge none (deterministic gate) · verdict: closed (FAIL at step 0 (reach below the power bar; device cost rules out a default))

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## Outgoing

- ruled out: [X-161] HEADPASS-X2b: HEADPASS-X2b: neighbour chunks + budgeted dense candidates appended after the keep step (a reranker added nothing over X2b) → https://r4topunk.github.io/boar-research/map/x-161.md

Read chapter 9, Knowledge packs: https://r4topunk.github.io/boar-research/research/packs.md

## Facts cited {#facts}

Resolve every [F-…] marker in https://r4topunk.github.io/boar-research/data/facts.json. Each line gives the claim, the number with its metric family, set and status, judge, n, seeds, CI, date and caveat.

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- [F-551] R74 Reranker-chosen append (X3): replay. reach 111/109 vs 117; 21.4 s/item · set UNKNOWN (status UNKNOWN) · judge UNKNOWN · n UNKNOWN · seeds UNKNOWN · CI not computed · caveat: why closed: step-0 FAIL
- [F-1110] HEADPASS-X3: cross-encoder reranker picks appended chunks → 111/109 vs 117; 3.9 s/item (slower and below the bar)

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Cite as: r4to, independent researcher. RatLab — A Boar Research (2026), research record 1.0, as of 2026-10-25. Text and data CC BY 4.0. Fact ids or a link must travel with a quote. How to cite: https://r4topunk.github.io/boar-research/cite/ · https://r4topunk.github.io/boar-research/CITATION.cff.

AI-reviewed, not clinically reviewed. Nothing here is medical advice.