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# crewborg performance log

Dated, appendable entries tracking the **crewborg** policy's trajectory in the
**crewrift** coworld. Each entry covers an optimization period: where the policy
started, where it ended, and what changed in between. Numbers are sourced from
the crewborg `version_log.md`, the lab `WORKING_CONTEXT.md`, the suspicion_lab
README/metrics, and `data/suspicion_weights.json` — nothing here is invented.

## 2026-06-12 — optimization period 2026-06-09 → 2026-06-12 (v16 → v25 champion)

**Coworld:** crewrift (Crewrift social-deduction league; scoring win +100, task +1
×8, kill +10, vote-timeout −10).

**Starting point.** The period opens with crewborg as a mid-pack crewmate-leaning
policy carrying real bugs. The earliest logged versions (v16–v17, 2026-06-09/10)
were voting-audit and vote-confirmation builds; v17 (`bd97b769`) ranked 2nd by
mean score in a 100-episode rotated top-7 batch but was still a passive imposter.
Through v18–v19 the work was infrastructure: SDK-routed tracing (v18) and an
offline nav-bake (v19) that cut the first-tick spawn freeze from ~13,700ms to
52–72ms (~200×). The strategic baseline that this period had to improve on was a
policy that, as imposter, **never got ejected but under-killed** (~1.55–1.7
kills/game vs a field top of ~2.0) and, as crew, voted itself out — its own sprite
leaked into the roster, saturating self-suspicion and causing self-ejection.

**Trajectory and what changed.**

- **v20 (meeting overhaul):** unified witnessed catches into the event log, added
  clear-suspect voting, accusation chat, Accuse mode, imposter meetings, and
  spaCy chat-NLP. Hosted eval exposed a `meeting_decision.nlp=failed` bug on every
  imposter episode (missing `click` → spaCy never loaded). Not submitted.
- **v21 (`52fc8572`):** fixed the chat-NLP load (added `click`); chat NLP reached
  `ready`. Submitted, became live champion — but still carried the self-vote bug.
- **v22 (`40e29a8c`):** the **self-vote bugfix** — learn `self_color` and exclude
  it from tailing/scoring/`top_suspect`/the ballot. Verified it votes real other
  players, never itself. Submitted (`sub_9a4b4fa9`).
- **v23 (BE_DUMB experiment):** stripped Pretend/Evade to pure aggression. Kills
  2.25→2.47/g (+10%) but ejection 14%→40% (~3×) — pure aggression a bad trade,
  rejected. Confirmed the kill cap is the 500-tick cooldown + victim isolation,
  not blending time.
- **v24 (`b725a6e1`, "kill sooner"):** `SEARCH_LEAD_TICKS` 100→250; fake tasks
  held only while a crewmate is visible. **Controlled 2-imp A/B (100 eps/arm,
  fixed roster): kills 1.37→1.58/g (+15%), t=2.21, p=0.027 significant**; win
  +6% (p=0.40, not significant) at zero ejection cost. Submitted (`sub_e6969016`).
  Its league debut (first 7 Competition rounds, ~480 eps): **rank 11/20** (44.15,
  mid-pack), **crew 25.1% win** (n=406), **imposter 69.4% win** @ **1.79 kills/g**
  (now field-top kill tier). Diagnosis: the imposter kill→win link is weak; the
  gap to leaders is crew-side conversion, not kill volume.
- **v25 (`36204c43`, the fitted suspicion model — ENDING POINT / champion):**
  pivoted to the crew lever. Built the suspicion_lab data-science pipeline
  (scrape → expand → dataset → L1 logistic-regression fit) and vendored fitted
  weights (`data/suspicion_weights.json`): trained 2026-06-12 on **1,857 games /
  196,427 rows, CV AUC 0.8124** (= the full-feature ceiling; CV log-loss 0.466).
  Added runtime social detectors (`social_evidence.py`: watched task completions,
  chat stances, attributed vote dots) plus the MeetingCall caller parse. Adopted a
  **crewmate vote bar of P≥0.9, no clear-leader rule.** Strongest learned cue:
  `tasks_completed_watched` at −10.82 (imposters produced ZERO across 62k labelled
  rows). Held-out decision sim @ P≥0.9: **94% imposter precision** (vs the legacy
  hand model's 42%), net +17.3/100 vs always-skip.

**Ending point (v25 champion).** Submitted 2026-06-12 (`sub_07dae14f`,
`lpm_c04b55cc`) and now champion. **A/B vs v24** (pinned roster, 40 eps × 2
configs): **crew win 22% → 35%** (+13pp, p=0.22, underpowered), with the mechanism
unambiguous — votes-at-crew **0.88 → 0.05/g**, **own ejection rate 52% → 2%**
(21/40 → 1/40), team crew-ejections 30 → 6, tasks-done-alive 95% → 100% and faster
(median tick 5323 → 4724); imposter regression scan clean (kills 0.89→1.30,
p=0.01 up; win noise; ejected 11%→7%). A larger **natural eval (200 eps, random
roles/seats rotating): crew win 43.8%** (n=146) — above RowDaBoat's 39.2%
benchmark — imposter 68.5% @ 1.43 kills/g held.

**Net trajectory.** The policy moved from a buggy, self-ejecting, passive-imposter
mid-pack player (v17 rank ~2nd-by-score in isolated batches but ~1.55 kills/g and
voting itself out) to a fitted-suspicion crew specialist: imposter kills lifted to
a field-top ~1.79/g (v24), then the decisive gain came on the crew side, where the
data-driven vote-restraint model (AUC 0.812) cut own-ejections 52%→2% and raised
crew win to ~35–44% — at or above the league's best crew benchmark. v25 is the
current champion; v26–v30 (button-runner interception, isolation-off) were all
experimental and rejected, confirming a third time that the imposter-kill lever is
structurally cooldown-bound (~1.27/g) and exhausted.

_Not findable in the supplied artifacts:_ a single point-in-time **league
leaderboard rank for v25** itself (the rank 11/20 figure is v24's debut; v25's
crew-win numbers come from A/B and natural-eval batches, not a league standings
snapshot), and an explicit period-start league rank for v16/v17 beyond
"2nd by mean score" within a private 100-episode batch.
