diff --git a/mcp-server/src/legal_mcp/services/block_writer.py b/mcp-server/src/legal_mcp/services/block_writer.py
index 8185a31..e02dec6 100644
--- a/mcp-server/src/legal_mcp/services/block_writer.py
+++ b/mcp-server/src/legal_mcp/services/block_writer.py
@@ -355,6 +355,7 @@ async def write_block(
     case_id: UUID,
     block_id: str,
     instructions: str = "",
+    effort_override: str | None = None,
 ) -> dict:
     """כתיבת בלוק יחיד בהחלטה.
 
@@ -362,6 +363,11 @@ async def write_block(
         case_id: מזהה התיק
         block_id: מזהה הבלוק (block-alef, block-he, block-yod, ...)
         instructions: הנחיות נוספות
+        effort_override: optional per-call reasoning effort (low/medium/high/
+            xhigh/max). When set, overrides BLOCK_CONFIG[block_id].effort for
+            THIS call only — used by the #208 model/effort calibration harness
+            to A/B efforts without mutating the pinned defaults. Production
+            callers leave it None and get the deterministic per-block effort.
 
     Returns:
         dict עם content, word_count, block_id, generation_type
@@ -472,7 +478,7 @@ async def write_block(
     # reasoning effort so generation is structurally deterministic — these were
     # previously NOT forwarded (the source of inconsistency). model/effort flow
     # through claude_session.query → `claude -p --model … --effort …`.
-    effort = block_cfg.get("effort", DEFAULT_EFFORT)
+    effort = effort_override or block_cfg.get("effort", DEFAULT_EFFORT)
     timeout = claude_session.LONG_TIMEOUT if effort in _LONG_EFFORTS else claude_session.DEFAULT_TIMEOUT
     content = await claude_session.query(
         prompt,
@@ -485,6 +491,10 @@ async def write_block(
     sources = await _collect_block_sources(case_id, block_id)
     sources["case_law_ids"] = _precedent_case_law_ids
     result = _build_result(block_id, content, block_cfg)
+    # Record the EFFECTIVE effort (override wins) so the harness can attribute
+    # the measured distance to the effort that actually produced the text.
+    if result.get("effort") is not None:
+        result["effort"] = effort
     result["sources"] = sources
     return result
 
diff --git a/mcp-server/src/legal_mcp/services/style_distance.py b/mcp-server/src/legal_mcp/services/style_distance.py
index 5718d85..843e661 100644
--- a/mcp-server/src/legal_mcp/services/style_distance.py
+++ b/mcp-server/src/legal_mcp/services/style_distance.py
@@ -15,6 +15,7 @@ import re
 from uuid import UUID
 
 from legal_mcp.services import db
+from legal_mcp.services.learning_loop import compute_diff_stats
 from legal_mcp.services.lessons import ANTI_PATTERNS, GOLDEN_RATIOS, canonical_outcome
 
 logger = logging.getLogger(__name__)
@@ -122,6 +123,93 @@ def golden_ratio_adherence(block_word_counts: dict[str, int], outcome: str) -> d
     return {"outcome": outcome, "total_words": total, "sections": sections, "max_deviation": max_dev}
 
 
+def split_final_by_section(final_text: str) -> dict[str, str]:
+    """Group a signed final decision into golden-ratio sections (#208 calibration).
+
+    Reuses the SAME structure-aware splitter as measure_corpus_ratios
+    (chunker._split_into_sections + _CHUNK_SECTION_TO_GOLDEN) — no parallel
+    parsing path (G2). Returns {golden_section: concatenated_text} for the
+    sections that map to an AI block (background/claims/discussion/summary).
+    A section type that does not map (e.g. headers) is dropped, never silently
+    folded into another section. Best-effort: an unsplittable final returns {}.
+    """
+    from legal_mcp.services.chunker import _split_into_sections
+
+    by_section: dict[str, list[str]] = {}
+    for stype, stext in _split_into_sections(final_text or ""):
+        g = _CHUNK_SECTION_TO_GOLDEN.get(stype)
+        if g and stext.strip():
+            by_section.setdefault(g, []).append(stext.strip())
+    return {sec: "\n\n".join(parts) for sec, parts in by_section.items()}
+
+
+def block_distance_to_final(
+    block_id: str,
+    regenerated_text: str,
+    final_section_text: str,
+    outcome: str,
+    section_target_total_words: int | None = None,
+) -> dict:
+    """Distance of ONE regenerated block from the chair's matching final section.
+
+    The per-(block, effort) measurement cell for the #208 model/effort
+    calibration harness. Pure/deterministic (no LLM, no DB) — reuses the
+    existing style-distance primitives so the harness has no parallel metric
+    path (G2 / INV-G8 eval-harness):
+
+      • change_percent          — compute_diff_stats(regen, final_section)
+                                   (learning_loop, the SAME diff the pairing
+                                   ledger stores). Lower ⇒ the draft already
+                                   reads like the final ⇒ less chair rewriting.
+      • anti_pattern_total      — count_anti_patterns(regen) (lessons.ANTI_PATTERNS).
+                                   Lower ⇒ closer to Dafna's continuous-narrative
+                                   voice; the CLEANEST style signal (07-learning §0.7).
+      • golden_ratio_deviation_pp — |regen %-of-total − final %-of-total| for this
+                                   block's section. 0 ⇒ same structural weight as
+                                   the final. Requires the final's total words
+                                   (section_target_total_words); otherwise None
+                                   (we never fabricate a denominator).
+
+    Returns the three metrics + a single composite `distance` (normalized,
+    lower=closer) the harness ranks efforts by.
+    """
+    outcome = canonical_outcome(outcome)
+    diff = compute_diff_stats(regenerated_text or "", final_section_text or "")
+    change_percent = diff["change_percent"]
+    anti_total = count_anti_patterns(regenerated_text or "")["total"]
+
+    section = _BLOCK_TO_SECTION.get(block_id)
+    regen_words = len((regenerated_text or "").split())
+    final_words = len((final_section_text or "").split())
+    ratio_dev: float | None = None
+    if section and section_target_total_words and section_target_total_words > 0:
+        # Replace the final's own block contribution with the regen's, holding
+        # the rest of the final constant, to compare structural weight fairly.
+        regen_total = section_target_total_words - final_words + regen_words
+        if regen_total > 0:
+            regen_pct = regen_words / regen_total * 100
+            final_pct = final_words / section_target_total_words * 100
+            ratio_dev = round(abs(regen_pct - final_pct), 1)
+
+    # Composite: normalize each component to ~[0,1] and average the present ones.
+    # change_percent/100, anti_total/10 (10+ hits is already very bad), ratio/20.
+    comps: list[float] = [min(change_percent / 100.0, 1.0), min(anti_total / 10.0, 1.0)]
+    if ratio_dev is not None:
+        comps.append(min(ratio_dev / 20.0, 1.0))
+    distance = round(sum(comps) / len(comps), 4)
+
+    return {
+        "block_id": block_id,
+        "section": section,
+        "regen_words": regen_words,
+        "final_words": final_words,
+        "change_percent": change_percent,
+        "anti_pattern_total": anti_total,
+        "golden_ratio_deviation_pp": ratio_dev,
+        "distance": distance,
+    }
+
+
 async def style_distance(case_number: str) -> dict:
     """Assemble the 3 style-distance components for one case (T7)."""
     case = await db.get_case_by_number(case_number)
diff --git a/scripts/SCRIPTS.md b/scripts/SCRIPTS.md
index d319a34..b5bc609 100644
--- a/scripts/SCRIPTS.md
+++ b/scripts/SCRIPTS.md
@@ -76,6 +76,7 @@
 | `calibrate_halacha_dedup.py` | python | **#82.1** — כיול ספי ה-dedup הלקסיקלי (#82.3) מול gold-set הניקוי. קורא `halacha-cleanup-manifest-*.csv` (זוגות duplicate↔survivor מתויגי-אדם), טוען טקסט-survivor מה-DB, ו-sweep של (jaccard_min × levenshtein_min) עם P/R/F1, מסמן את נקודת-העבודה המוגדרת. אימת ש-(0.55, 0.70) → **precision 1.0** (אפס false-merge), recall 0.30 — מתאים לאיתות-משני שחוסם auto-approve. `--manifest <path>`. רץ עם venv של mcp-server | חד-פעמי — כיול (בוצע 2026-06-06) |
 | `ab_halacha_opus48.py` | python | **A/B לא-הרסני לחילוץ הלכות (Claude)** — מריץ מחדש חילוץ הלכות על פסק-דין בודד דרך מודל/effort נבחרים (`AB_MODEL`/`AB_EFFORT`, ברירת-מחדל `claude-opus-4-8`/`xhigh`) ומשווה לסטטיסטיקות ההלכות הקיימות ב-DB **בלי למחוק/לכתוב כלום**. משכפל את `halacha_extractor.extract()` (אותם פרומפטים, בחירת-צ'אנקים, אימות-ציטוט) ומחליף רק את קריאת ה-LLM ב-`claude -p --model --effort`. מפיק `data/ab_halacha_<case>_<effort>.json`. הרצה: `DOTENV_PATH=/home/chaim/.env DATA_DIR=.../data .venv/bin/python scripts/ab_halacha_opus48.py <case_law_id>`. **ממצא 2026-05-31 (שטיין 1128-08-20):** Opus 4.8@xhigh חילץ 51 מול 124 בייצור (100% quote-verified מול 96%) אך ביטחון מכויל-נמוך יותר (חציון 0.75 מול 0.82) — ולכן **לא** מקטין את תור-האישור-הידני תחת sweep אוטו-אישור conf≥0.78 (26 מול 24). שיפור איכות, לא צמצום-תור. | ידני (החלטת מודל-חילוץ) |
 | `ab_halacha_codex.py` | python | **A/B לא-הרסני לחילוץ הלכות (Codex/gpt-5.5)** — עמית ל-`ab_halacha_opus48` אך מחליף את `claude -p` ב-`codex exec --model gpt-5.5` (אימות ChatGPT, ללא OPENAI_API_KEY). אותם פרומפטים ואותו הסקת quote-verification. הפלט האחרון של הסוכן (`-o FILE`) נפענח כ-JSON. `AB_MODEL` (default `gpt-5.5`), `AB_REASONING` low/medium/high/xhigh (default `medium`), `AB_CONCURRENCY` (default 1), `CODEX_BIN`. מפיק `data/ab_halacha_codex_<case>_<model>_<reasoning>.json`. הרצה: `DOTENV_PATH=/home/chaim/.env DATA_DIR=.../data mcp-server/.venv/bin/python scripts/ab_halacha_codex.py <case_law_id>`. **ממצא 2026-06-17 (8181-21 האוניברסיטה העברית):** gpt-5.5@medium חילץ 27 מול 28 של Opus (quote-verified 100%/100%), ביטחון חציון 0.86 מול 0.78 — אך **0 פריטים מתחת ל-0.7** (לעומת 9/28 של Opus = 32%), דבר המצביע על over-confidence. holding↑ (12 מול 7), procedural↓ (4 מול 7). **מסקנה: ריאלי כ-fallback חירום; לא מוכן לייצור ללא כיול-ביטחון.** | ידני (בנצ'מרק מודל codex) |
+| `calibrate_effort.py` | python | **#208 (WS5/Q1, INV-G8 eval-harness) — כיול model×effort של הכותב מול הסופיים.** A/B per-(תיק,בלוק,effort) על `draft_final_pairs` בעלי `final_text`: מייצר מחדש כל בלוק דרך מסלול-הייצור (`block_writer.write_block(effort_override=…)` → `claude_session.query` → `claude -p`, Opus 4.8 נעוץ, **מקומי-בלבד**) ומודד מול ה**סקשן** המתאים בסופי דרך `services/style_distance.block_distance_to_final` (מקור-מדידה יחיד, G2): `change_percent` (compute_diff_stats) · `anti_pattern_total` (`lessons.ANTI_PATTERNS`, הסיגנל הנקי-לסגנון) · `golden_ratio_deviation_pp` · `distance` מרוכב. **ממליץ** per-בלוק על ה-effort בעל ה-distance-הממוצע-הנמוך (לצד ברירת-המחדל מ-#204). מפיק `data/eval/effort-calibration-<ts>.{json,md}`. ⚠️ **גודל-מדגם מודפס בראש הדוח — עדות-כיוון, לא רגרסיה** (מעט סופיים-עלויים). `--self-test` (offline, אפס DB/CLI — מוכיח את לוגיקת-המדידה) · `--dry-run` (תכנון-גריד) · `--efforts`/`--blocks`/`--case`/`--repeats`. **חובה מקומי** (claude CLI; לא בקונטיינר/worktree-ללא-CLI). הרצה: `POSTGRES_PASSWORD=… mcp-server/.venv/bin/python scripts/calibrate_effort.py`. | ידני — לכיול ברירות-effort של הכותב |
 | `monitor_halacha_quality.py` | python | מנטר איכות חילוץ הלכות. בודק drift של `avg(confidence)` בין baseline היסטורי לחלון אחרון. מחזיר JSON מטריקות + alert ב-stderr אם drift > threshold (ברירת מחדל 5%). 2 סדרות: trusted (approved+published) ו-all_extracted. תומך `--window N` / `--threshold X` / `--min-sample N` / `--silent` / `--exit-on-alert`. רץ ב-container או מקומית עם `mcp-server/.venv` (אין תלות ב-LLM, רק SQL). **תזמון מומלץ**: `0 8 * * 1` (יום ראשון 08:00, שבועי) | `0 8 * * 1` (לתזמן) |
 | `audit_training_corpus.py` | python | audit של `style_corpus` — לכל החלטה: שדות מטא-דאטה מאוכלסים (`summary`/`outcome`/`key_principles`/`appeal_subtype`/`subject_categories`), קישור ל-`documents` (FK + chunks + embeddings). מפיק `data/audit/corpus-YYYY-MM-DD.json` + summary בקונסול. דרוש `POSTGRES_URL` או POSTGRES_*. אין תלויות חיצוניות מלבד asyncpg. **רץ מהמכונה המקומית** (לא קונטיינר) — חיבור ישיר ל-Postgres :5433 | ידני / קדם-עבודה לפני enrichment של מטא-דאטה |
 | `backfill_style_exemplars.py` | python | **T1 (style-acquisition)** — מאכלס `style_exemplars` מקורפוס דפנה (`style_corpus` + `internal_committee` chair=דפנה): מפצל לסעיפים (`chunker._split_into_sections`) → פסקאות (25-450 מילים) → embed (Voyage) → שמירה עם `section`/`outcome`/`practice_area`. מאפשר לכותב לאחזר פסקאות-בלוק אמיתיות של דפנה (T2/T3). מקור-סגנון בלבד (INV-LRN5). אידמפוטנטי (מנקה per-decision). `--dry-run` (default) / `--apply`. דורש POSTGRES_URL + Voyage. **רץ מקומית** (venv). | ידני (`python scripts/backfill_style_exemplars.py --apply`) |
diff --git a/scripts/calibrate_effort.py b/scripts/calibrate_effort.py
new file mode 100644
index 0000000..2c8f064
--- /dev/null
+++ b/scripts/calibrate_effort.py
@@ -0,0 +1,419 @@
+#!/usr/bin/env python3
+"""#208 (WS5 / Q1, INV-G8 eval-harness) — model×effort calibration vs the finals.
+
+Empirically picks the per-block reasoning `effort` whose regenerated block lands
+CLOSEST to עו"ד דפנה תמיר's signed final, over the EXISTING `draft_final_pairs`
+ledger. This is the calibration INV-G8 / 07-learning §0.7 ask for: stop choosing
+the per-block effort defaults (#204: ה=medium, ו=medium, ז=high, ח=medium, ט=high)
+"by feel".
+
+WHAT IT MEASURES (per (case, block, effort) cell — the A/B grid):
+  Regenerate `block` for `case` via block_writer.write_block(effort_override=…)
+  (the PRODUCTION generation path → claude_session.query → `claude -p`, pinned
+  Opus 4.8, local-only), then score the regenerated block against the matching
+  SECTION of the final via services.style_distance.block_distance_to_final:
+    • change_percent           — word-diff regen↔final-section (compute_diff_stats)
+    • anti_pattern_total       — lessons.ANTI_PATTERNS hits in the regen (cleanest
+                                 style signal — see §0.7 warning below)
+    • golden_ratio_deviation_pp — structural-weight gap vs the final
+    • distance                 — normalized composite (lower = closer to Dafna)
+  No parallel metric path: it reuses style_distance + learning_loop (G2).
+
+RECOMMENDATION: for each block, the effort with the lowest MEAN composite distance
+across cases (ties → fewer anti-patterns → lower change_percent). Reported next to
+the #204 current default so a regression/improvement is visible.
+
+⚠️ SAMPLE-SIZE CAVEAT (honored, not hidden): very few cases have an uploaded final
+(draft_final_pairs.final_text non-empty). The report prints n_finals PROMINENTLY and
+labels the output DIRECTIONAL EVIDENCE, not a regression. With n<3 per block the
+recommendation is advisory only; the chair/operator decides whether to adopt.
+
+⚠️ change_percent mixes style with content completeness (07-learning §0.7): the chair
+sometimes doubles length for missing substance. anti_pattern_total is the cleaner
+style signal — the report surfaces both, and the composite down-weights neither
+silently.
+
+GENERATION PATH (do not violate — reference_claude_generation_path / claude_session
+docstring): write_block → claude_session.query → `claude -p` uses the local claude.ai
+session. It runs ONLY on the host where the `claude` CLI exists (NOT the legal-ai
+container, NOT a symlinked worktree without CLI access). Hence the live A/B is
+host-only; --self-test proves the measurement logic offline with zero model calls.
+
+Usage (mcp-server venv; live needs POSTGRES + the `claude` CLI on the host):
+    PY=/home/chaim/legal-ai/mcp-server/.venv/bin/python
+    $PY scripts/calibrate_effort.py --self-test            # offline proof, no DB/CLI
+    POSTGRES_PASSWORD=… POSTGRES_HOST=127.0.0.1 POSTGRES_PORT=5433 \
+        $PY scripts/calibrate_effort.py                    # live A/B over finals
+    … --efforts low,medium,high,xhigh                      # override the effort grid
+    … --blocks block-he,block-vav                          # restrict to some blocks
+    … --case 8137-11-24                                    # a single case
+    … --repeats 2                                          # avg N gens/cell (noise)
+    … --dry-run                                            # plan the grid, no model calls
+"""
+from __future__ import annotations
+
+import argparse
+import asyncio
+import json
+import os
+import sys
+from datetime import datetime, timezone
+from pathlib import Path
+from statistics import mean
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(REPO_ROOT / "mcp-server" / "src"))
+
+if "POSTGRES_URL" not in os.environ:
+    os.environ["POSTGRES_URL"] = (
+        f"postgres://{os.environ.get('POSTGRES_USER','legal_ai')}:"
+        f"{os.environ.get('POSTGRES_PASSWORD','')}@"
+        f"{os.environ.get('POSTGRES_HOST','127.0.0.1')}:"
+        f"{os.environ.get('POSTGRES_PORT','5433')}/"
+        f"{os.environ.get('POSTGRES_DB','legal_ai')}"
+    )
+
+OUT_DIR = REPO_ROOT / "data" / "eval"
+
+# Only the AI blocks that map to a golden-ratio section can be scored against the
+# final's matching section (split_final_by_section). Template blocks (א-ד, יב) are
+# deterministic template-fill — no effort knob. block-yod (discussion) is out of
+# WS5's interim scope but mappable, so it's included when present.
+CALIBRATABLE_BLOCKS = ["block-he", "block-vav", "block-zayin", "block-chet", "block-tet", "block-yod", "block-yod-alef"]
+DEFAULT_EFFORTS = ["low", "medium", "high", "xhigh"]
+VALID_EFFORTS = {"low", "medium", "high", "xhigh", "max"}
+
+
+# ── pure helpers (offline-testable) ──────────────────────────────────────────
+def recommend_effort(cells: list[dict]) -> dict | None:
+    """Pick the best effort for ONE block from its scored cells.
+
+    cells: [{"effort","distance","anti_pattern_total","change_percent","n"}].
+    Lowest mean composite distance wins; ties broken by fewer anti-patterns,
+    then lower change_percent. Pure → unit-tested in --self-test.
+    """
+    if not cells:
+        return None
+    ranked = sorted(
+        cells,
+        key=lambda c: (c["distance"], c["anti_pattern_total"], c["change_percent"]),
+    )
+    return ranked[0]
+
+
+def aggregate_cell(per_run: list[dict]) -> dict:
+    """Mean each metric across repeated generations of the same (case, block, effort)."""
+    if not per_run:
+        return {"distance": 1.0, "anti_pattern_total": 0.0, "change_percent": 100.0,
+                "golden_ratio_deviation_pp": None, "n": 0}
+    ratios = [r["golden_ratio_deviation_pp"] for r in per_run if r.get("golden_ratio_deviation_pp") is not None]
+    return {
+        "distance": round(mean(r["distance"] for r in per_run), 4),
+        "anti_pattern_total": round(mean(r["anti_pattern_total"] for r in per_run), 2),
+        "change_percent": round(mean(r["change_percent"] for r in per_run), 2),
+        "golden_ratio_deviation_pp": round(mean(ratios), 2) if ratios else None,
+        "n": len(per_run),
+    }
+
+
+def _current_default(block_id: str) -> str | None:
+    from legal_mcp.services.block_writer import BLOCK_CONFIG, DEFAULT_EFFORT
+    cfg = BLOCK_CONFIG.get(block_id, {})
+    if cfg.get("model") != "ai":
+        return None
+    return cfg.get("effort", DEFAULT_EFFORT)
+
+
+# ── self-test (no DB, no model) ──────────────────────────────────────────────
+def _self_test() -> int:
+    ok = True
+
+    def chk(name, cond):
+        nonlocal ok
+        ok = ok and cond
+        print(f"  {name:42} {'ok' if cond else 'FAIL'}")
+
+    # block_distance_to_final: regen identical to final-section ⇒ change ~0,
+    # distance dominated by anti-patterns (0 here) ⇒ ~0.
+    from legal_mcp.services.style_distance import (
+        block_distance_to_final, split_final_by_section,
+    )
+    final_section = "לפנינו ערר על החלטת הוועדה המקומית. " * 40
+    d_same = block_distance_to_final("block-he", final_section, final_section, "rejection",
+                                     section_target_total_words=len(final_section.split()))
+    chk("identical regen ⇒ change_percent==0", d_same["change_percent"] == 0.0)
+    chk("identical regen ⇒ anti==0", d_same["anti_pattern_total"] == 0)
+    chk("identical regen ⇒ distance small", d_same["distance"] < 0.05)
+
+    # A regen full of anti-patterns (markdown headers / bullet lists) scores worse
+    # than clean continuous narrative, holding the final fixed.
+    clean = "אנו סבורים כי דין הערר להידחות. כידוע, הלכה פסוקה היא. " * 20
+    dirty = "## כותרת\n- נקודה ראשונה\n- נקודה שנייה\n* עוד נקודה\n### תת\n" * 10
+    d_clean = block_distance_to_final("block-yod", clean, final_section, "rejection",
+                                      section_target_total_words=len(final_section.split()))
+    d_dirty = block_distance_to_final("block-yod", dirty, final_section, "rejection",
+                                      section_target_total_words=len(final_section.split()))
+    chk("dirty regen has more anti-patterns", d_dirty["anti_pattern_total"] > d_clean["anti_pattern_total"])
+    chk("dirty regen ⇒ larger distance", d_dirty["distance"] > d_clean["distance"])
+
+    # ratio deviation is None when no total provided (never fabricated)
+    d_noratio = block_distance_to_final("block-he", clean, final_section, "rejection")
+    chk("no total ⇒ ratio deviation None", d_noratio["golden_ratio_deviation_pp"] is None)
+
+    # split_final_by_section returns mapped golden sections only.
+    sample_final = (
+        "רקע עובדתי\nהמקרקעין נשוא הערר. " * 10 + "\n\n"
+        "תמצית טענות הצדדים\nהעוררים טוענים כי. " * 10 + "\n\n"
+        "דיון והכרעה\nאנו סבורים כי. " * 10
+    )
+    secs = split_final_by_section(sample_final)
+    chk("split maps to golden sections", set(secs).issubset(
+        {"background", "claims", "discussion", "summary"}))
+    chk("split found ≥1 section", len(secs) >= 1)
+
+    # recommend_effort: lowest distance wins; tie → fewer anti-patterns.
+    rec = recommend_effort([
+        {"effort": "low", "distance": 0.40, "anti_pattern_total": 5, "change_percent": 40, "n": 1},
+        {"effort": "high", "distance": 0.20, "anti_pattern_total": 2, "change_percent": 25, "n": 1},
+        {"effort": "xhigh", "distance": 0.20, "anti_pattern_total": 1, "change_percent": 22, "n": 1},
+    ])
+    chk("recommend picks lowest distance", rec["distance"] == 0.20)
+    chk("recommend tie → fewer anti-patterns", rec["effort"] == "xhigh")
+    chk("recommend empty ⇒ None", recommend_effort([]) is None)
+
+    # aggregate_cell: means + ratio drops Nones, keeps n.
+    agg = aggregate_cell([
+        {"distance": 0.2, "anti_pattern_total": 2, "change_percent": 20, "golden_ratio_deviation_pp": 3.0},
+        {"distance": 0.4, "anti_pattern_total": 4, "change_percent": 30, "golden_ratio_deviation_pp": None},
+    ])
+    chk("aggregate distance mean", agg["distance"] == 0.3)
+    chk("aggregate n counted", agg["n"] == 2)
+    chk("aggregate ratio skips None", agg["golden_ratio_deviation_pp"] == 3.0)
+
+    print("ALL PASS" if ok else "*** FAILURES ***")
+    return 0 if ok else 1
+
+
+# ── live A/B (host-only — needs DB + `claude` CLI) ───────────────────────────
+async def _finals_for_calibration(case_filter: str | None) -> list[dict]:
+    """draft_final_pairs whose final_text is populated (the held-out comparison set)."""
+    from legal_mcp.services import db
+    pairs = await db.list_draft_final_pairs(limit=500)
+    out: list[dict] = []
+    for p in pairs:
+        if case_filter and p.get("case_number") != case_filter:
+            continue
+        full = await db.get_draft_final_pair(p["id"])
+        if full and (full.get("final_text") or "").strip():
+            out.append(full)
+    return out
+
+
+async def _score_cell(case_id, block_id: str, effort: str, final_section: str,
+                      final_total_words: int, outcome: str, repeats: int) -> dict:
+    """Generate `block_id` at `effort` `repeats` times; score each vs the final section."""
+    from legal_mcp.services import block_writer
+    from legal_mcp.services.style_distance import block_distance_to_final
+    runs: list[dict] = []
+    for _ in range(repeats):
+        res = await block_writer.write_block(case_id, block_id, effort_override=effort)
+        scored = block_distance_to_final(
+            block_id, res.get("content", ""), final_section, outcome,
+            section_target_total_words=final_total_words,
+        )
+        runs.append(scored)
+    agg = aggregate_cell(runs)
+    agg["effort"] = effort
+    agg["runs"] = runs
+    return agg
+
+
+async def _run(args) -> dict:
+    from uuid import UUID
+    from legal_mcp.services import db
+    from legal_mcp.services.lessons import canonical_outcome
+    from legal_mcp.services.style_distance import split_final_by_section, _BLOCK_TO_SECTION
+
+    efforts = args.efforts
+    blocks = args.blocks
+    finals = await _finals_for_calibration(args.case)
+
+    cases_meta = []
+    for f in finals:
+        case = await db.get_case_by_number(f["case_number"]) if f.get("case_number") else None
+        if not case:
+            continue
+        decision = await db.get_decision_by_case(UUID(case["id"]))
+        outcome = canonical_outcome((decision or {}).get("outcome", "rejection"))
+        sections = split_final_by_section(f.get("final_text", ""))
+        final_total_words = len((f.get("final_text", "") or "").split())
+        cases_meta.append({
+            "case_number": f["case_number"], "case_id": case["id"],
+            "outcome": outcome, "sections": sections, "final_total_words": final_total_words,
+        })
+
+    # grid plan: (block → cases that have its section)
+    plan: dict[str, list[dict]] = {}
+    for block_id in blocks:
+        section = _BLOCK_TO_SECTION.get(block_id)
+        plan[block_id] = [c for c in cases_meta if section and c["sections"].get(section)]
+
+    total_cells = sum(len(plan[b]) for b in blocks) * len(efforts) * args.repeats
+    grid_summary = {
+        "n_finals": len(cases_meta),
+        "finals": [c["case_number"] for c in cases_meta],
+        "blocks": blocks, "efforts": efforts, "repeats": args.repeats,
+        "total_generations": total_cells,
+        "per_block_n": {b: len(plan[b]) for b in blocks},
+    }
+
+    if args.dry_run:
+        return {"dry_run": True, "grid": grid_summary, "by_block": {}}
+
+    by_block: dict[str, dict] = {}
+    for block_id in blocks:
+        section = _BLOCK_TO_SECTION.get(block_id)
+        per_effort_runs: dict[str, list[dict]] = {e: [] for e in efforts}
+        per_case: list[dict] = []
+        for c in plan[block_id]:
+            final_section = c["sections"][section]
+            case_cells = []
+            for effort in efforts:
+                cell = await _score_cell(
+                    UUID(c["case_id"]), block_id, effort, final_section,
+                    c["final_total_words"], c["outcome"], args.repeats,
+                )
+                per_effort_runs[effort].append(cell)
+                case_cells.append({k: cell[k] for k in
+                                   ("effort", "distance", "anti_pattern_total",
+                                    "change_percent", "golden_ratio_deviation_pp", "n")})
+            per_case.append({"case_number": c["case_number"], "cells": case_cells})
+
+        # mean across cases for each effort → one comparable row per effort
+        effort_rows = []
+        for effort in efforts:
+            rows = per_effort_runs[effort]
+            if not rows:
+                continue
+            ratios = [r["golden_ratio_deviation_pp"] for r in rows if r.get("golden_ratio_deviation_pp") is not None]
+            effort_rows.append({
+                "effort": effort,
+                "distance": round(mean(r["distance"] for r in rows), 4),
+                "anti_pattern_total": round(mean(r["anti_pattern_total"] for r in rows), 2),
+                "change_percent": round(mean(r["change_percent"] for r in rows), 2),
+                "golden_ratio_deviation_pp": round(mean(ratios), 2) if ratios else None,
+                "n": len(rows),
+            })
+        rec = recommend_effort(effort_rows)
+        by_block[block_id] = {
+            "section": section,
+            "current_default": _current_default(block_id),
+            "recommended": rec["effort"] if rec else None,
+            "efforts": effort_rows,
+            "per_case": per_case,
+        }
+
+    return {"dry_run": False, "grid": grid_summary, "by_block": by_block}
+
+
+def _ts() -> str:
+    return datetime.now(timezone.utc).strftime("%Y%m%dT%H%M%SZ")
+
+
+def _write_report(result: dict, ts: str) -> tuple[Path, Path]:
+    OUT_DIR.mkdir(parents=True, exist_ok=True)
+    jp = OUT_DIR / f"effort-calibration-{ts}.json"
+    mp = OUT_DIR / f"effort-calibration-{ts}.md"
+    jp.write_text(json.dumps(result, ensure_ascii=False, indent=2), encoding="utf-8")
+
+    g = result["grid"]
+    n = g["n_finals"]
+    lines = [
+        f"# #208 — כיול model×effort מול הסופיים — {ts}\n",
+        f"> ⚠️ **גודל-מדגם: {n} סופיים** ({', '.join(g['finals']) or '—'}). "
+        "זוהי **עדות-כיוון, לא רגרסיה** — מעט תיקים בעלי סופי-עלוי. "
+        "ההמלצה אדוויזורית; ההכרעה בידי היו\"ר/המפעיל.\n",
+        f"- בלוקים: {', '.join(g['blocks'])}",
+        f"- efforts: {', '.join(g['efforts'])} · repeats/cell: {g['repeats']}",
+        f"- סך ייצורי-מודל: {g['total_generations']}",
+        "",
+    ]
+    if result.get("dry_run"):
+        lines += ["## DRY-RUN — תכנון הגריד בלבד (ללא ייצור)\n",
+                  "| block | #cases | current default |", "|---|---|---|"]
+        for b in g["blocks"]:
+            lines.append(f"| {b} | {g['per_block_n'].get(b,0)} | {_current_default(b) or '—'} |")
+        mp.write_text("\n".join(lines) + "\n", encoding="utf-8")
+        return jp, mp
+
+    lines += ["## המלצה per-בלוק (distance נמוך = קרוב יותר לדפנה)\n",
+              "| block | section | current | **recommended** | n |", "|---|---|---|---|---|"]
+    for b, bd in result["by_block"].items():
+        rec = bd.get("recommended") or "—"
+        mark = "" if rec == bd.get("current_default") else " ⬅︎"
+        n_b = bd["efforts"][0]["n"] if bd.get("efforts") else 0
+        lines.append(f"| {b} | {bd.get('section','')} | {bd.get('current_default') or '—'} | **{rec}**{mark} | {n_b} |")
+    lines.append("")
+    for b, bd in result["by_block"].items():
+        lines += [f"### {b} ({bd.get('section','')})\n",
+                  "| effort | distance | anti_total | change% | ratioΔpp | n |",
+                  "|---|---|---|---|---|---|"]
+        for r in bd.get("efforts", []):
+            star = " ⭐" if r["effort"] == bd.get("recommended") else ""
+            ratio = r["golden_ratio_deviation_pp"]
+            lines.append(
+                f"| {r['effort']}{star} | {r['distance']:.4f} | {r['anti_pattern_total']} | "
+                f"{r['change_percent']} | {ratio if ratio is not None else '—'} | {r['n']} |")
+        lines.append("")
+    lines.append("> change% מערבב סגנון עם שלמות-תוכן (07-learning §0.7); "
+                 "anti_total הוא הסיגנל הנקי-יותר לסגנון.\n")
+    mp.write_text("\n".join(lines) + "\n", encoding="utf-8")
+    return jp, mp
+
+
+async def main() -> int:
+    ap = argparse.ArgumentParser(description="#208 model/effort calibration harness")
+    ap.add_argument("--self-test", action="store_true", help="offline measurement-logic proof (no DB/CLI)")
+    ap.add_argument("--dry-run", action="store_true", help="plan the A/B grid over existing finals, no model calls")
+    ap.add_argument("--efforts", default=",".join(DEFAULT_EFFORTS),
+                    help=f"comma effort grid (default {','.join(DEFAULT_EFFORTS)})")
+    ap.add_argument("--blocks", default=",".join(CALIBRATABLE_BLOCKS),
+                    help="comma block ids to calibrate")
+    ap.add_argument("--case", default=None, help="restrict to a single case_number")
+    ap.add_argument("--repeats", type=int, default=1, help="generations per cell (avg out gen noise)")
+    args = ap.parse_args()
+
+    if args.self_test:
+        return _self_test()
+
+    args.efforts = [e.strip() for e in args.efforts.split(",") if e.strip()]
+    bad = [e for e in args.efforts if e not in VALID_EFFORTS]
+    if bad:
+        print(f"invalid effort(s): {bad}. valid: {sorted(VALID_EFFORTS)}", file=sys.stderr)
+        return 2
+    args.blocks = [b.strip() for b in args.blocks.split(",") if b.strip()]
+    bad_b = [b for b in args.blocks if b not in CALIBRATABLE_BLOCKS]
+    if bad_b:
+        print(f"non-calibratable block(s): {bad_b}. valid: {CALIBRATABLE_BLOCKS}", file=sys.stderr)
+        return 2
+
+    result = await _run(args)
+    ts = _ts()
+    jp, mp = _write_report(result, ts)
+
+    g = result["grid"]
+    print(f"CALIBRATION: {g['n_finals']} finals — DIRECTIONAL EVIDENCE, not a regression")
+    if g["n_finals"] == 0:
+        print("  no finals with final_text in draft_final_pairs — upload a signed final first.")
+    elif result.get("dry_run"):
+        print(f"  dry-run: {g['total_generations']} generations planned across {len(g['blocks'])} blocks")
+    else:
+        for b, bd in result["by_block"].items():
+            print(f"  {b:16} current={bd.get('current_default') or '—':6} "
+                  f"→ recommended={bd.get('recommended') or '—'}")
+    print(f"  report: {mp}")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(asyncio.run(main()))