Pengo E004 review: causal hypothesis and the reader-only test

Research diary

6 October 2026. Original protocols, results, videos and source contracts are preserved. These corrections qualify the interpretation and govern new trials.

ReviewResponse and evidence
Y1The claim that the bottleneck shifted from survival to planner strategy is a hypothesis. Observations establish zero detected death in the retained segment and25consecutive decisions without official reduction. They do not isolate algorithm quality from the invisible egg targets: eggs were UNKNOWN at all1290E003 ACT3 observations.
Y2PENGO-E020 is the reader-only counterfactual. Same6017reset prefix, original E003 planner/heuristic/action order, original oracle_v2 controller, width4/depth4/20workers and all original budgets/watchdog. Only egg observation changes. E018 and the causal heuristic are excluded. The redesigned E005 is deferred.
Y3All18 original arithmetic mismatches have concrete state explanations; definitions and frame sets are below. Their native contexts were reviewed. This is internal RAM consistency, not independent pixel-reader accuracy.
Y4Capacity is measured from each act’s initialized native header and full coordinate table. Baseline and Rack diagnostics agree ACT1=6,ACT2=6,ACT3=8. Rack v1 had zero admissions, v2 reproduced onlyACT1..3 within the fixed30000frames/replica. ACT4+ remains UNKNOWN; this later-act validation request is still open. No Rack tape can seed E020 or any game result.
Y5Causal candidate contact is6778; native confirmed-crush animation begins6783; official acknowledgement is6895. The event record retains all three, with contact as the onset. A contact alone is not automatically a confirmed kill. Ack gives no second credit. E020 retains the original counter-based watchdog to avoid a second intervention.
Y6Future no-progress stops are NUL for the registered configuration. Normal budget exhaustion, no-safe-branch and unsupported representation also fail that configuration. Infrastructure interruption is separately INCOMPLETE. Historical E003/E010 outcomes keep their original frozen labels with this forward classification stated.
Y7W1–W6 are already applied in the separate current editorial v2, public at z0bCW2dLh9w. The original MP4s are unchanged and nonpublishable. Current SHA256c8d0bdde79d0cb48c851a8cbc3f87dd115d554e4237203e93985f79e18ab4520; first frame and postdeath7324 were re-inspected for this review.

What the original mismatch comparison measured

The original E004 v2 arithmetic was:

number of nonzero actor raw-state slots (four slots) + valid nonzero egg coordinates (eight observed ACT3 slots)

compared with native official objective counter at program-space0x8d98 in the same observation. It did not compare with pixels, independent object labels, the pixel-agent extractor or the egg header. Native replay equivalence supports the reliability of those recorded observations; it does not make the arithmetic an independent semantic ground truth.

Corpus/frameOriginal sum vs counterNative eventReconciliation
E0036753..6763,11frames3populated actor slots+3table entries=6 vs7Egg entry6 temporarily zero while its ice moves from(7,9) downward; moving ice position is independently consistent in object/sprite observations. Header stays4. Entry returns at(7,11) on6764.Add the one transported egg, not a newly created egg or kill.
E0096468..6473,6frames3populated slots+3table entries=6 vs7Entry6 is absent while its ice travels from(7,9) upward; header stays4. It returns at(7,8) on6474.Add the transported egg once.
E0096432,1frame3populated slots+5table entries=8 vs7An already crushed actor changes from points/raw12 to retirement/raw13. The following frame6433 starts a replacement hatch/raw15 at(3,13) and removes that egg coordinate.Exclude the retired old generation at6432. A nonzero slot is not necessarily a remaining enemy.

Thus all18 original discrepancies are explained at the observed update boundaries, with no new simulation. The eight native rendered examples show block motion, crush-points and hatch context. The egg inside an ordinary ice block is not directly visible in these images; its identity requires offline table history. This does not establish pixel-agent egg-memory performance.

Two additional header-update boundaries

The new strict reader admission found E0096501 and6895: the egg coordinate removal precedes native egg-header reduction by one frame. These are not the seven original arithmetic mismatches, because that comparison did not use the header. The opt-in reader retains UNKNOWN on those two frames and never zero. Its frozen validation admits1290/1290 known E003 and1280/1282 known E009 frames, including both transport sequences; all non-egg phase/state fields are unchanged. First overstrict validation failure and its separate corrected validator are retained. Later-act capacity is not inferred from this ACT3 test.

Interpretation of the counterfactual

If reader-only E020 completes, it supports a causal contribution from the egg representation under this one frozen start/configuration. If it stagnates again, the reader fix alone was insufficient. That does not prove the planner is the only cause: controller limits, residual update boundaries and finite search budgets remain possible contributors. These are predeclared interpretation limits, not a post-result reinterpretation or silent parameter change.

9,790 remains best verified planner trajectory at tape end,9,390last alive, death7299,ACT3incomplete.9,090 is the historical E003 observation.304,000 remains a numeric target; no new score search, diamond assumption or leaderboard claim.

Evidence: data/pengo/e004/review-y3-mismatches-v1; data/pengo/e019/rack-egg-capacity-v1 and v2; data/pengo/e020/egg-reader-admission-v1/failure.json and v1-1/result.json; docs/pengo/PENGO-VIDEO-9790-REVIEW-v2.md and publication receipts.

Verified native replay frames show two egg-block transports and retirement/hatch context

Derived mismatch evidence · Reader admission · Retained review response · Current corrected video.