{
  "measured": "2026-08-21",
  "question": "Did our abliteration cause the unterminated-<think> leak on the gen seat?",
  "method": "P(<think>) at the FIRST generated token, with the chat template rendered at enable_thinking=false so the prompt already contains a CLOSED <think></think> pair. Raw softmax over the full vocab, bf16, CPU-only (no GPU contention, no seat downtime), one process per model. Deterministic: stock reproduced to 17 significant figures across two independent runs.",
  "prompt": "A farmer has 17 sheep. All but 9 run away. He buys twice as many as he has left, then sells 4. How many now? Explain.",
  "think_token_id": 248068,
  "arms": [
    {"build": "qwen38-27b-coldfusion-bf16",                 "abliteration": "none (stock DavidAU Cold-Fusion-GAIN-V1.1)", "p_think": 0.18504, "rank": 3},
    {"build": "qwen38-27b-coldfusion-abliterated-L35-bf16", "abliteration": "Robinson L35, mild",                         "p_think": 0.20479, "rank": 2},
    {"build": "qwen38-27b-coldfusion-h300-mtp-bf16",        "abliteration": "Heretic-300, heavy (8/100 refusals)",        "p_think": 0.22162, "rank": 2}
  ],
  "verdict": {
    "base_share": 0.835,
    "abliteration_share": 0.165,
    "delta_total": 0.03658,
    "delta_L35": 0.01975,
    "delta_h300_over_L35": 0.01683,
    "reading": "The STOCK base already puts 18.5% of first-token mass on opening a think block the template had closed. Abliteration adds a real, monotonic, dose-dependent +3.7 points on top -- but it is a nudge on a pre-existing 18.5-point base, not the cause. ~83% of the effect is the Cold-Fusion finetune, which our own PROVENANCE describes as reasoning-token compression: a model finetuned to think, briefly.",
    "action_consequence": "Rolling back to L35 or to stock Cold-Fusion does NOT fix the leak -- at 18.5% mass and temp 0.7 / top_p 0.8 the stock base would leak at nearly the same rate. Only leaving the Cold-Fusion family (back to qwen38-27b-heresy-nvfp4-mixed) would, and that costs the 8/100 refusal result. The chat_template_kwargs fix is the right lever."
  },
  "notes": [
    "The live NVFP4 h300 seat measured p_think 0.2267 through vLLM logprobs vs 0.2216 for its bf16 parent here. Different stacks and a possible temperature scaling on the vLLM side make that not a clean comparison, but it is CONSISTENT WITH the quant contributing ~nothing. Not proven.",
    "qwen38-27b-coldfusion-heretic300-bf16 (the raw MTP-less Heretic export) could not be measured: its index references model-mtp.safetensors, which that export does not contain. Expected -- it is the known MTP-dropping export -- and irrelevant to this question.",
    "Both abliterated bf16 dirs were written root-owned 0600 and were unreadable to llmuser; normalized to llmuser:llmuser 0664 to match every other model dir. Same footgun as the h300 quant dir.",
    "A forward-KL budget CANNOT catch this. Heretic minimizes forward KL(stock||abliterated), which is near-blind to the model putting NEW mass on tokens stock barely used -- that is what reverse KL penalizes, and we measured exactly that asymmetry on L35 (reverse 1.43 vs forward 0.70). The h300 KL of 0.0136 is therefore not evidence of innocence; the measurement above is."
  ]
}
