fix: model tiered sub-set artifact bonuses (the ACC discrepancy root cause)

Chasing the ~20 ACC validation gap led to the real cause: 13 newer sets
(id 35/36/47/48/58-66, e.g. IncreaseAccuracyAndSpeedWithSkillEffects,
BlockReflectDebuffAndHpAndDef) have pieces=0 and store their bonus in a
piece-count LADDER (`sub_sets`), where each tier's StatBonuses is the TOTAL at
that count (not multiplied, not cumulative). The hero gets the highest tier
whose `pieces` <= owned count. e.g. set 36: 1pc=+20 ACC, 2pc=+20 ACC & +10% SPD,
3pc=+40 ACC … up to 9pc. IL2CPP confirms via ArtifactSubSetInfo
(ArtifactCount + List<StatBonus> StatBonuses).

Our artifact_sets.json was stale (no sub_sets); the mod already emits them.
Refreshed it, added SUB_SET_BONUSES (id -> sorted [(pieces, {stat: value})])
in gear_constants, and applied the highest-tier-<=-count lookup in calc_stats.

Validation jumped: Venom/Geo/Arbiter ACC now EXACT (were -20/-20/-40); Ninja
ACC improved 40 (one tier). Remaining: smaller DEF outliers (Cardiel/Ninja),
likely Divine on ACC/DEF or another tier. Default calc_stats (sim) path
unaffected — sub-set bonuses route through set_pct/set_flat which the
mod-column path ignores; same 2 pre-existing regression failures.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: SnoopLawg

data/static/artifact_sets.json

@@ -1,9 +1,7 @@
 {
   "_meta": {
-    "fetched_at": "2026-05-01T18:14:45.259518+00:00",
-    "scene": "Village",
-    "mod_version": "2.0-bepinex",
-    "unity": "6000.0.60f1"
+    "generated_by": "/artifact-sets-truth (sub_sets 2026-06-23)",
+    "note": "tiered sub-set bonuses included"
   },
   "sets": [
     {

tools/cb_optimizer.py

@@ -64,7 +64,7 @@
 # Set bonuses + names — sourced from data/static/artifact_sets.json via
 # gear_constants. SET_BONUSES is value-correct (live-game derived); SET_NAMES
 # is display-friendly. See gear_constants.py for details.
-from gear_constants import SET_BONUSES, SET_NAMES  # noqa: E402
+from gear_constants import SET_BONUSES, SET_NAMES, SUB_SET_BONUSES  # noqa: E402
 
 # Import canonical slot/set names from central module
 try:
@@ -412,6 +412,26 @@ def calc_stats(hero, artifacts, account, hypothetical=False):
                         flat_b[stat] += val * num_complete
                 else:
                     set_pct[stat] += val * num_complete
+        # Tiered sub-set sets (id 35/36/47/48/58-66): pick the highest tier
+        # whose `pieces` <= owned count; its StatBonuses is the TOTAL (not
+        # multiplied, not cumulative). e.g. set 36 with 1 piece = +20 ACC.
+        ladder = SUB_SET_BONUSES.get(s_id)
+        if ladder:
+            tier = None
+            for pieces, sm in ladder:
+                if cnt >= pieces:
+                    tier = sm
+                else:
+                    break
+            if tier:
+                active_sets.add(s_id)
+                for stat, val in tier.items():
+                    if stat in (ACC, RES):
+                        set_flat[stat] += val
+                        if not use_mod_artifact_bonus:
+                            flat_b[stat] += val
+                    else:
+                        set_pct[stat] += val
 
     # Lore of Steel (mastery 500343, Support tree): +15% to all set
     # bonuses.

tools/gear_constants.py

@@ -188,6 +188,9 @@ def to_artifact_stat_kind_id(stat_id, is_flat):
 SET_PIECES: dict[int, int] = {}                      # id → 2 / 4 (or 0 for special)
 SET_KIND_IDS: dict[int, str] = SET_INTERNAL_NAMES    # legacy alias for existing consumers
 SET_BONUSES: dict[int, tuple[int, dict[int, float]]] = {}
+# Tiered sub-set ladders: id → [(pieces, {stat_id: value}), …] ascending.
+# Apply the highest tier whose `pieces` <= the hero's owned count.
+SUB_SET_BONUSES: dict[int, list] = {}
 
 # Prefer the live game-truth file (data/static/artifact_rules.json) which is
 # generated by `tools/refresh_artifact_truth.py`. Falls back to the older
@@ -246,6 +249,37 @@ def to_artifact_stat_kind_id(stat_id, is_flat):
                 _stat_map[_sid] = _v          # game-truth value (overwrites/augments)
             if _stat_map:
                 SET_BONUSES[_id] = (_pieces, _stat_map)
+
+        # SUB-SET (tiered) SETS — 13 newer sets (id 35/36/47/48/58-66) have
+        # `pieces=0` and store their bonus in `sub_sets`: a piece-count ladder
+        # where each tier's StatBonuses is the TOTAL at that count (NOT
+        # cumulative, NOT multiplied). e.g. set 36: 1pc=+20 ACC, 2pc=+20 ACC &
+        # +10% SPD, 3pc=+40 ACC & +10% SPD … up to 9pc. The hero gets the
+        # highest tier whose `pieces` <= their owned count. Build a sorted
+        # ladder per set: SUB_SET_BONUSES[id] = [(pieces, {stat_id: value}), …].
+        # Values: absolute → raw (flat); percent → ×100 (matches SET_BONUSES).
+        for _row in _rows:
+            _id = _row.get("id")
+            _subs = _row.get("sub_sets") or []
+            if _id is None or not _subs:
+                continue
+            _ladder = []
+            for _ss in _subs:
+                _cnt = _ss.get("pieces")
+                _sm = {}
+                for _b in _ss.get("stat_bonuses") or []:
+                    _sid = _name_to_stat.get(_b.get("stat"))
+                    if _sid is None:
+                        continue
+                    _v = _b.get("value", 0)
+                    if not _b.get("absolute"):
+                        _v = round(_v * 100, 2)
+                    _sm[_sid] = _v
+                if _cnt and _sm:
+                    _ladder.append((_cnt, _sm))
+            if _ladder:
+                _ladder.sort(key=lambda t: t[0])
+                SUB_SET_BONUSES[_id] = _ladder
 except Exception:
     pass  # keep the singular-stat table if the plural file is unavailable