RESULT 55: 单侧偏置首次直接定量(线性∝β,0.3-1%@3e-3,2.7σ;BBP线真空点补上); 逐样本符号+batch平均=无偏(用户命题四层两β全验证,偏置消到噪声地板,零代价); 预登记推论:若bsign挡不住下沉则cent护甲非消偏

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014FAPDWQ49M5Ye3NpTndTpn

1 files changed, 17 insertions, 0 deletions

diff --git a/docs/campaign/CASCADE_ABLATION_PLAN.md b/docs/campaign/CASCADE_ABLATION_PLAN.md
index 6dd93e5..4cd5f3a 100644
--- a/docs/campaign/CASCADE_ABLATION_PLAN.md
+++ b/docs/campaign/CASCADE_ABLATION_PLAN.md
@@ -568,6 +568,23 @@ direction), not training-under-fault; wave-2 = co-training with faults injected
 
 
 
+### RESULT 55 (2026-07-20): SINGLE-SIDED BIAS DIRECTLY QUANTIFIED (the BBP-thread gap) —
+real, linear in beta, 0.3-1% of grad norm @3e-3; PER-SAMPLE SIGN + BATCH AVERAGE = UNBIASED
+(user's claim VERIFIED at zero measurable cost).
+probe_bias @plain2_s35000, 16 batches, beta {3e-3,1e-2}, selfcheck 3e-9: plain rel_bias
+|mean(gEP-gBP)|/|mean(gBP)|: w2_b11 0.0035->0.0114 (x3.26 ~ beta ratio 3.33, 2.7sigma over sem
+0.0013->0.0042); qkv_b0 0.0106->0.0325; all four layers >sem with ~x3.1-3.4 scaling => the
+Laborieux O(beta) term measured directly on a 72M transformer. PSIGN (per-sample random nudge
+sign, read re-flipped): bias -> noise floor in EVERY row (w2_b11: 0.0014 vs sem 0.0014), both
+betas; sem unchanged vs plain => debiasing is FREE (no extra phase, no variance penalty at B=8;
+improves with B — the scale-native estimator, supersedes per-batch bsign in theory).
+Batch size alone does NOT debias (bias survives expectation); it only debiases AFTER the
+per-sample sign flip makes the O(beta) term batch-antisymmetric — user's "sign+大batch=无偏"
+is the correct composition. PRE-REGISTERED corollary: bias is only 0.3-1%, so if the RUNNING
+bsign crown fails to stop the ceiling sink (user predicts it will fail), cent's armor is NOT
+debiasing — it must be a variance/geometry property of the symmetric read; new puzzle.
+In flight: fw72m_bsign (GPU1/3, per-batch sign), fw72m_ratchet (GPU0 queued, halve-only).
+
 ### RESULT 54 (2026-07-20): THE CEILING SINKS ∝1/σ² AS TRAINING SHARPENS — no fixed β survives;
 "fixed β never explodes" was FALSE (it STALLS: endgame skip-storm = frozen training). β must DESCEND.
 User caught it: "固定β永不炸个屁！你一直skip还训不训了？" — dead right.