diff --git a/routes/shared.py b/routes/shared.py
index 7980373..f80e1c2 100644
--- a/routes/shared.py
+++ b/routes/shared.py
@@ -195,7 +195,7 @@ from models.state import AI_PROFILES
 # ══════════════════════════════════════════════════════════════
 # Java / Sim Helpers (extracted to services/forge_runner.py)
 from services.forge_runner import (
-    _find_java17, get_java17, build_java_command, parse_dck_file,
+    _find_java17, get_java17, build_java_command,
     run_batch_subprocess, _run_process_blocking,
     _run_deepseek_batch_thread, _get_deepseek_brain,
 )
diff --git a/services/forge_runner.py b/services/forge_runner.py
index f64d91a..933a2b6 100644
--- a/services/forge_runner.py
+++ b/services/forge_runner.py
@@ -1,19 +1,27 @@
 """Forge batch simulation runner: Java discovery, command building, process management."""
 import asyncio
 import datetime
+import json
 import logging
 import os
 import re
 import subprocess
+import sys
 import threading
 import time
+from datetime import datetime as _datetime
 from pathlib import Path
 from typing import Optional
 
 from models.state import CFG, BatchState
-from services.deck_service import parse_dck_file
+from services.deck_service import parse_dck_file, _load_deck_cards_by_name
 
 log = logging.getLogger("lab.batch")
+log_sim = logging.getLogger("commander_ai_lab.sim")
+
+# Global DeepSeek brain instance (lazy-initialized)
+_deepseek_brain = None
+_deepseek_lock = threading.Lock()
 
 
 def _find_java17() -> str:
@@ -138,4 +146,308 @@ async def run_batch_subprocess(
         use_learned_policy=use_learned_policy, **kwargs,
     )
     loop = asyncio.get_event_loop()
-    await loop.run_in_executor(None, _run_process_blocking, state, cmd)
\ No newline at end of file
+    await loop.run_in_executor(None, _run_process_blocking, state, cmd)
+
+
+def _get_deepseek_brain():
+    """Get or create the global DeepSeek brain instance."""
+    global _deepseek_brain
+    if _deepseek_brain is None:
+        with _deepseek_lock:
+            if _deepseek_brain is None:
+                try:
+                    src_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'src')
+                    src_dir = os.path.normpath(src_dir)
+                    if src_dir not in sys.path:
+                        sys.path.insert(0, src_dir)
+                    from commander_ai_lab.sim.deepseek_brain import DeepSeekBrain, DeepSeekConfig
+                    cfg = DeepSeekConfig()
+                    # Allow env var overrides
+                    if os.environ.get('DEEPSEEK_API_BASE'):
+                        cfg.api_base = os.environ['DEEPSEEK_API_BASE']
+                    if os.environ.get('DEEPSEEK_MODEL'):
+                        cfg.model = os.environ['DEEPSEEK_MODEL']
+                    cfg.log_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'logs', 'decisions')
+                    cfg.log_dir = os.path.normpath(cfg.log_dir)
+                    _deepseek_brain = DeepSeekBrain(cfg)
+                except Exception as e:
+                    log_sim.error(f'Failed to initialize brain: {e}')
+                    return None
+    return _deepseek_brain
+
+
+def _run_deepseek_batch_thread(
+    state: BatchState,
+    deck_names: list,
+    num_games: int,
+    output_path: str,
+):
+    """Run batch simulation using Python sim engine + DeepSeek AI opponent."""
+    try:
+        src_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'src')
+        src_dir = os.path.normpath(src_dir)
+        if src_dir not in sys.path:
+            sys.path.insert(0, src_dir)
+
+        from commander_ai_lab.sim.models import Card
+        from commander_ai_lab.sim.deepseek_engine import DeepSeekGameEngine
+        from commander_ai_lab.sim.rules import enrich_card
+
+        state.log_lines.append('[DeepSeek Batch] Initializing DeepSeek brain...')
+        brain = _get_deepseek_brain()
+        if brain and not brain._connected:
+            brain.check_connection()
+        if not brain or not brain._connected:
+            state.error = 'DeepSeek LLM not connected. Go to Simulator > DeepSeek and connect first.'
+            state.running = False
+            return
+
+        state.log_lines.append(f'[DeepSeek Batch] Connected to {brain.config.model}')
+
+        # Load all decks
+        # ── Look up historical win rates from past batch results ──
+        deck_win_rates = {}  # deck_name -> float (0-100)
+        try:
+            results_dir = CFG.results_dir
+            if os.path.isdir(results_dir):
+                for fname in sorted(os.listdir(results_dir), reverse=True):
+                    if fname.startswith('batch-') and fname.endswith('.json'):
+                        try:
+                            with open(os.path.join(results_dir, fname), 'r') as rf:
+                                past = json.loads(rf.read())
+                            for dd in past.get('decks', []):
+                                dname = dd.get('deckName', '')
+                                wr = dd.get('winRate')
+                                if dname and wr is not None and dname not in deck_win_rates:
+                                    deck_win_rates[dname] = float(wr)
+                        except Exception:
+                            pass
+        except Exception:
+            pass
+
+        loaded_decks = {}
+        deck_meta = {}  # deck_name -> {commander_name, color_identity, archetype}
+        for dn in deck_names:
+            raw_cards = _load_deck_cards_by_name(dn)
+            if not raw_cards:
+                state.log_lines.append(f'[DeepSeek Batch] WARNING: Could not load deck "{dn}", skipping.')
+                continue
+
+            # Detect commander and color identity from card data
+            commander_name = ''
+            color_identity_set = set()
+            deck_objs = []
+            for cd in raw_cards:
+                c = Card(name=cd['name'])
+                if cd.get('type_line'): c.type_line = cd['type_line']
+                if cd.get('cmc'): c.cmc = float(cd['cmc'])
+                if cd.get('power') and cd.get('toughness'):
+                    c.power = str(cd['power'])
+                    c.toughness = str(cd['toughness'])
+                    c.pt = c.power + '/' + c.toughness
+                if cd.get('oracle_text'): c.oracle_text = cd['oracle_text']
+                if cd.get('mana_cost'): c.mana_cost = cd['mana_cost']
+                if cd.get('keywords'):
+                    kw = cd['keywords']
+                    if isinstance(kw, str):
+                        try: kw = json.loads(kw)
+                        except Exception: kw = []
+                    if isinstance(kw, list): c.keywords = kw
+                # Set is_commander flag from DB data
+                if cd.get('is_commander'):
+                    c.is_commander = True
+                    commander_name = cd['name']
+                # Collect color identity
+                ci_str = cd.get('color_identity', '')
+                if ci_str:
+                    try:
+                        ci_parsed = json.loads(ci_str) if isinstance(ci_str, str) else ci_str
+                        if isinstance(ci_parsed, list):
+                            for color in ci_parsed:
+                                color_identity_set.add(color)
+                    except Exception:
+                        pass
+                enrich_card(c)
+                deck_objs.append(c)
+
+            # Infer archetype from deck composition
+            creature_count = sum(1 for c in deck_objs if c.is_creature())
+            removal_count = sum(1 for c in deck_objs if c.is_removal)
+            ramp_count = sum(1 for c in deck_objs if c.is_ramp)
+            avg_cmc = sum(c.cmc or 0 for c in deck_objs if not c.is_land()) / max(sum(1 for c in deck_objs if not c.is_land()), 1)
+            oracle_all = ' '.join((c.oracle_text or '').lower() for c in deck_objs)
+            has_combo_text = any(kw in oracle_all for kw in ['you win the game', 'infinite', 'extra turn'])
+
+            if has_combo_text:
+                archetype = 'combo'
+            elif creature_count >= 30 and avg_cmc <= 2.8:
+                archetype = 'aggro'
+            elif removal_count >= 10 or (creature_count <= 18 and avg_cmc >= 3.2):
+                archetype = 'control'
+            else:
+                archetype = 'midrange'
+
+            color_identity_list = sorted(list(color_identity_set))
+            deck_meta[dn] = {
+                'commander_name': commander_name,
+                'color_identity': color_identity_list,
+                'archetype': archetype,
+                'win_rate': deck_win_rates.get(dn),
+            }
+
+            loaded_decks[dn] = deck_objs
+            cmdr_info = f' (Commander: {commander_name})' if commander_name else ''
+            wr_info = f' [History: {deck_win_rates[dn]:.0f}% WR]' if dn in deck_win_rates else ''
+            state.log_lines.append(f'[DeepSeek Batch] Loaded deck "{dn}" ({len(deck_objs)} cards, {archetype}){cmdr_info}{wr_info}')
+
+        if not loaded_decks:
+            state.error = 'No decks could be loaded.'
+            state.running = False
+            return
+
+        # Build matchup schedule: each deck plays num_games vs DeepSeek AI
+        deck_list = list(loaded_decks.keys())
+        games_per_deck = max(1, num_games // len(deck_list))
+        total_games = games_per_deck * len(deck_list)
+        state.total_games = total_games
+
+        state.log_lines.append(f'[DeepSeek Batch] Running {games_per_deck} games per deck \u00d7 {len(deck_list)} decks = {total_games} total')
+
+        engine = DeepSeekGameEngine(
+            brain=brain,
+            ai_player_index=0,  # AI pilots deck_a (user's deck) with full intelligence
+            max_turns=25,
+            record_log=True,
+            ml_log=True,
+        )
+
+        start_time = time.time()
+        all_deck_results = []
+        completed = 0
+
+        for deck_name in deck_list:
+            deck_a = loaded_decks[deck_name]
+            # Generate a training opponent for each game
+            from commander_ai_lab.lab.experiments import _generate_training_deck
+
+            deck_stats = {
+                'deckName': deck_name,
+                'wins': 0, 'losses': 0, 'totalGames': games_per_deck,
+                'totalTurns': 0, 'totalDamageDealt': 0, 'totalDamageReceived': 0,
+                'totalSpellsCast': 0, 'totalCreaturesPlayed': 0,
+                'games': [],
+            }
+
+            meta = deck_meta.get(deck_name, {})
+            dk_archetype = meta.get('archetype', 'midrange')
+            dk_commander = meta.get('commander_name', '')
+            dk_colors = meta.get('color_identity', [])
+            dk_win_rate = meta.get('win_rate')
+
+            for g in range(games_per_deck):
+                try:
+                    deck_b = _generate_training_deck()
+                    game_id = f'ds-{state.batch_id}-{deck_name[:12]}-g{g+1}'
+                    result = engine.run(
+                        deck_a, deck_b,
+                        name_a=deck_name + ' (AI)',
+                        name_b='Training Opponent',
+                        game_id=game_id, archetype=dk_archetype,
+                        commander_name=dk_commander,
+                        color_identity=dk_colors,
+                        win_rate=dk_win_rate,
+                    )
+                    gd = result.to_dict()
+                    gd['gameNumber'] = g + 1
+                    deck_stats['games'].append(gd)
+
+                    if result.winner == 0:
+                        deck_stats['wins'] += 1
+                    else:
+                        deck_stats['losses'] += 1
+                    deck_stats['totalTurns'] += result.turns
+                    if result.player_a_stats:
+                        deck_stats['totalDamageDealt'] += result.player_a_stats.damage_dealt
+                        deck_stats['totalDamageReceived'] += result.player_a_stats.damage_received
+                        deck_stats['totalSpellsCast'] += result.player_a_stats.spells_cast
+                        deck_stats['totalCreaturesPlayed'] += result.player_a_stats.creatures_played
+
+                    state.log_lines.append(
+                        f'[Game {completed + 1}/{total_games}] {deck_name} (AI-piloted) \u2192 '
+                        f'{"WIN" if result.winner == 0 else "LOSS"} (turn {result.turns})'
+                    )
+                except Exception as ge:
+                    state.log_lines.append(f'[Game {completed + 1}/{total_games}] ERROR: {ge}')
+                    deck_stats['games'].append({'error': str(ge), 'gameNumber': g + 1})
+
+                completed += 1
+                state.completed_games = completed
+
+            n = deck_stats['totalGames']
+            deck_stats['winRate'] = round(deck_stats['wins'] / n * 100, 1) if n > 0 else 0.0
+            deck_stats['avgTurns'] = round(deck_stats['totalTurns'] / n, 1) if n > 0 else 0.0
+            deck_stats['avgDamageDealt'] = round(deck_stats['totalDamageDealt'] / n, 1) if n > 0 else 0.0
+            deck_stats['avgDamageReceived'] = round(deck_stats['totalDamageReceived'] / n, 1) if n > 0 else 0.0
+            deck_stats['avgSpellsCast'] = round(deck_stats['totalSpellsCast'] / n, 1) if n > 0 else 0.0
+            deck_stats['avgCreaturesPlayed'] = round(deck_stats['totalCreaturesPlayed'] / n, 1) if n > 0 else 0.0
+            # Include deck intelligence metadata
+            deck_stats['archetype'] = dk_archetype
+            deck_stats['commander'] = dk_commander
+            deck_stats['colorIdentity'] = dk_colors
+            if dk_win_rate is not None:
+                deck_stats['priorWinRate'] = dk_win_rate
+            all_deck_results.append(deck_stats)
+
+        elapsed = time.time() - start_time
+        ds_stats = brain.get_stats() if brain else {}
+
+        # Build result in compatible format
+        batch_result = {
+            'metadata': {
+                'batchId': state.batch_id,
+                'timestamp': _datetime.now().isoformat(),
+                'completedGames': completed,
+                'threads': 1,
+                'elapsedMs': int(elapsed * 1000),
+                'engine': 'deepseek',
+                'model': brain.config.model if brain else 'unknown',
+            },
+            'decks': all_deck_results,
+            'deepseekStats': ds_stats,
+        }
+
+        # Write ML decision JSONL for the training pipeline
+        ml_decisions = engine.flush_ml_decisions()
+        if ml_decisions:
+            ml_jsonl_path = os.path.join(CFG.results_dir, f'ml-decisions-ds-{state.batch_id}.jsonl')
+            os.makedirs(os.path.dirname(ml_jsonl_path) or '.', exist_ok=True)
+            with open(ml_jsonl_path, 'w', encoding='utf-8') as mf:
+                for dec in ml_decisions:
+                    mf.write(json.dumps(dec) + '\n')
+            state.log_lines.append(f'[ML Data] Wrote {len(ml_decisions)} decision snapshots to {os.path.basename(ml_jsonl_path)}')
+        else:
+            state.log_lines.append('[ML Data] No decision snapshots captured (0 decisions)')
+
+        # Save to results dir
+        os.makedirs(os.path.dirname(output_path), exist_ok=True)
+        with open(output_path, 'w', encoding='utf-8') as f:
+            json.dump(batch_result, f, indent=2, default=str)
+
+        state.result_path = output_path
+        elapsed_ms = int(elapsed * 1000)
+        state.elapsed_ms = elapsed_ms
+        state.running = False
+        state.completed_games = total_games
+
+        state.log_lines.append(f'[DeepSeek Batch] Complete: {completed} games in {elapsed:.1f}s')
+        for ds in all_deck_results:
+            state.log_lines.append(f'  {ds["deckName"]}: {ds["wins"]}W-{ds["losses"]}L ({ds["winRate"]}% WR)')
+
+        log_sim.info(f'Batch {state.batch_id} complete: {completed} games in {elapsed:.1f}s')
+
+    except Exception as e:
+        import traceback
+        state.error = str(e)
+        state.running = False
+        state.log_lines.append(f'[DeepSeek Batch] FATAL: {e}')
+        traceback.print_exc()
\ No newline at end of file