diff --git a/run_benchmark.ps1 b/run_benchmark.ps1
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+++ b/run_benchmark.ps1
@@ -0,0 +1,310 @@
+#!/usr/bin/env pwsh
+<#
+.SYNOPSIS
+    Commander AI Lab — full benchmark pipeline (Issue #153)
+
+.DESCRIPTION
+    Chains all four steps of the Forge-vs-Synthetic eval benchmark:
+      1. Train baseline model (synthetic self-play)
+      2. Train Forge model (--data-source forge)
+      3. Eval both checkpoints vs Forge built-in (200 games each)
+      4. Compare results with Fisher's exact test
+
+    Writes all artefacts to:
+      ml/models/checkpoints/baseline-synthetic/
+      ml/models/checkpoints/forge-trained/
+      results/eval-baseline.json
+      results/eval-forge.json
+      results/compare-result.json   ← pass/fail verdict
+
+.PARAMETER Iterations
+    PPO training iterations for each model. Default: 100
+
+.PARAMETER EpisodesPerIter
+    Self-play / Forge episodes per iteration. Default: 64
+
+.PARAMETER EvalGames
+    Evaluation games per model. Default: 200
+
+.PARAMETER Threads
+    Parallel Forge workers for eval. Default: 4
+
+.PARAMETER Seed
+    Optional RNG seed (passed to both eval runs for reproducibility).
+
+.PARAMETER ForgeResultsDir
+    Directory where Forge writes ml-decisions-forge-*.jsonl files.
+    Default: results
+
+.PARAMETER ForgeBatchId
+    Batch ID prefix used when the Forge producer writes JSONL files.
+    Default: forge-batch
+
+.PARAMETER ForgeNumGames
+    Total Forge games the producer will consume during Forge training.
+    Default: 256
+
+.PARAMETER MinDelta
+    Minimum absolute win-rate improvement to pass the benchmark. Default: 0.05
+
+.PARAMETER Alpha
+    Significance level for Fisher's exact test. Default: 0.05
+
+.PARAMETER SkipTraining
+    Skip both training steps (use existing checkpoints). Useful for re-running eval only.
+
+.PARAMETER SkipEval
+    Skip both eval steps (use existing result JSONs). Useful for re-running compare only.
+
+.EXAMPLE
+    # Full overnight run
+    .\run_benchmark.ps1
+
+.EXAMPLE
+    # Quick smoke-test with fewer iterations
+    .\run_benchmark.ps1 -Iterations 10 -EpisodePerIter 16 -EvalGames 50
+
+.EXAMPLE
+    # Re-run only the comparison from existing JSONs
+    .\run_benchmark.ps1 -SkipTraining -SkipEval
+#>
+
+[CmdletBinding()]
+param(
+    [int]    $Iterations      = 100,
+    [int]    $EpisodesPerIter = 64,
+    [int]    $EvalGames       = 200,
+    [int]    $Threads         = 4,
+    [int]    $Seed            = -1,
+    [string] $ForgeResultsDir = "results",
+    [string] $ForgeBatchId    = "forge-batch",
+    [int]    $ForgeNumGames   = 256,
+    [double] $MinDelta        = 0.05,
+    [double] $Alpha           = 0.05,
+    [switch] $SkipTraining,
+    [switch] $SkipEval
+)
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+
+# ── Paths ──────────────────────────────────────────────────────────────
+$BaselineDir    = "ml/models/checkpoints/baseline-synthetic"
+$ForgeDir       = "ml/models/checkpoints/forge-trained"
+$BaselineJson   = "results/eval-baseline.json"
+$ForgeJson      = "results/eval-forge.json"
+$CompareJson    = "results/compare-result.json"
+$LogDir         = "logs/benchmark"
+
+# ── Helpers ────────────────────────────────────────────────────────────
+function Banner([string]$msg) {
+    $line = "=" * 62
+    Write-Host ""
+    Write-Host $line -ForegroundColor Cyan
+    Write-Host "  $msg" -ForegroundColor Cyan
+    Write-Host $line -ForegroundColor Cyan
+    Write-Host ""
+}
+
+function Step([string]$msg) {
+    Write-Host "[$(Get-Date -Format 'HH:mm:ss')]  $msg" -ForegroundColor Yellow
+}
+
+function Ok([string]$msg) {
+    Write-Host "  ✓ $msg" -ForegroundColor Green
+}
+
+function Fail([string]$msg) {
+    Write-Host "  ✗ $msg" -ForegroundColor Red
+}
+
+function Run([string[]]$cmd) {
+    $display = $cmd -join " "
+    Step "Running: $display"
+    & $cmd[0] $cmd[1..($cmd.Length-1)]
+    if ($LASTEXITCODE -ne 0) {
+        Fail "Command failed (exit $LASTEXITCODE): $display"
+        exit $LASTEXITCODE
+    }
+}
+
+# ── Setup ──────────────────────────────────────────────────────────────
+$null = New-Item -ItemType Directory -Force -Path $LogDir, "results" | Out-Null
+
+$SeedArgs = @()
+if ($Seed -ge 0) { $SeedArgs = @("--seed", "$Seed") }
+
+$StartTime = Get-Date
+Banner "Commander AI Lab — Benchmark Pipeline (Issue #153)"
+
+Write-Host "  Iterations      : $Iterations"
+Write-Host "  Episodes/iter   : $EpisodesPerIter"
+Write-Host "  Eval games      : $EvalGames"
+Write-Host "  Eval threads    : $Threads"
+Write-Host "  Seed            : $(if ($Seed -ge 0) { $Seed } else { '(random)' })"
+Write-Host "  Min delta       : $($MinDelta * 100)%"
+Write-Host "  Alpha           : $Alpha"
+Write-Host "  Skip training   : $SkipTraining"
+Write-Host "  Skip eval       : $SkipEval"
+Write-Host ""
+
+# ══════════════════════════════════════════════════════════════════════
+# STEP 1 — Train baseline (synthetic self-play)
+# ══════════════════════════════════════════════════════════════════════
+if (-not $SkipTraining) {
+    Banner "Step 1/4 — Training baseline (synthetic)"
+    $t0 = Get-Date
+
+    Run @(
+        "python", "-m", "ml.training.ppo_trainer",
+        "--data-source",      "synthetic",
+        "--iterations",       "$Iterations",
+        "--episodes-per-iter","$EpisodesPerIter",
+        "--checkpoint-dir",   $BaselineDir,
+        "--save-every",       "10",
+        "--eval-every",       "5"
+    )
+
+    $elapsed = ((Get-Date) - $t0).TotalMinutes
+    Ok "Baseline training complete in $([math]::Round($elapsed,1)) min"
+    Ok "Checkpoints in: $BaselineDir"
+} else {
+    Step "Skipping training (--SkipTraining)"
+}
+
+# ══════════════════════════════════════════════════════════════════════
+# STEP 2 — Train Forge model
+# ══════════════════════════════════════════════════════════════════════
+if (-not $SkipTraining) {
+    Banner "Step 2/4 — Training Forge model"
+    $t0 = Get-Date
+
+    Run @(
+        "python", "-m", "ml.training.ppo_trainer",
+        "--data-source",       "forge",
+        "--iterations",        "$Iterations",
+        "--episodes-per-iter", "$EpisodesPerIter",
+        "--checkpoint-dir",    $ForgeDir,
+        "--forge-results-dir", $ForgeResultsDir,
+        "--forge-batch-id",    $ForgeBatchId,
+        "--forge-num-games",   "$ForgeNumGames",
+        "--save-every",        "10",
+        "--eval-every",        "5"
+    )
+
+    $elapsed = ((Get-Date) - $t0).TotalMinutes
+    Ok "Forge training complete in $([math]::Round($elapsed,1)) min"
+    Ok "Checkpoints in: $ForgeDir"
+} else {
+    Step "Skipping training (--SkipTraining)"
+}
+
+# ══════════════════════════════════════════════════════════════════════
+# STEP 3 — Eval baseline checkpoint
+# ══════════════════════════════════════════════════════════════════════
+if (-not $SkipEval) {
+    Banner "Step 3a/4 — Evaluating baseline checkpoint"
+
+    # Prefer best_ppo.pt, fall back to latest numbered checkpoint
+    $BaselinePt = "$BaselineDir/best_ppo.pt"
+    if (-not (Test-Path $BaselinePt)) {
+        $BaselinePt = Get-ChildItem "$BaselineDir/ppo_iter_*.pt" |
+                      Sort-Object Name -Descending |
+                      Select-Object -First 1 -ExpandProperty FullName
+    }
+    if (-not $BaselinePt -or -not (Test-Path $BaselinePt)) {
+        Fail "No checkpoint found in $BaselineDir — run training first or remove --SkipTraining"
+        exit 1
+    }
+    Step "Using checkpoint: $BaselinePt"
+    $t0 = Get-Date
+
+    Run (@(
+        "python", "scripts/eval_policy.py",
+        "--model",       $BaselinePt,
+        "--games",       "$EvalGames",
+        "--run-id",      "baseline-synthetic",
+        "--out",         $BaselineJson,
+        "--threads",     "$Threads"
+    ) + $SeedArgs)
+
+    $elapsed = ((Get-Date) - $t0).TotalMinutes
+    Ok "Baseline eval complete in $([math]::Round($elapsed,1)) min -> $BaselineJson"
+
+    # ── Eval Forge checkpoint ──────────────────────────────────────────
+    Banner "Step 3b/4 — Evaluating Forge checkpoint"
+
+    $ForgePt = "$ForgeDir/best_ppo.pt"
+    if (-not (Test-Path $ForgePt)) {
+        $ForgePt = Get-ChildItem "$ForgeDir/ppo_iter_*.pt" |
+                   Sort-Object Name -Descending |
+                   Select-Object -First 1 -ExpandProperty FullName
+    }
+    if (-not $ForgePt -or -not (Test-Path $ForgePt)) {
+        Fail "No checkpoint found in $ForgeDir — run training first or remove --SkipTraining"
+        exit 1
+    }
+    Step "Using checkpoint: $ForgePt"
+    $t0 = Get-Date
+
+    Run (@(
+        "python", "scripts/eval_policy.py",
+        "--model",   $ForgePt,
+        "--games",   "$EvalGames",
+        "--run-id",  "forge-trained",
+        "--out",     $ForgeJson,
+        "--threads", "$Threads"
+    ) + $SeedArgs)
+
+    $elapsed = ((Get-Date) - $t0).TotalMinutes
+    Ok "Forge eval complete in $([math]::Round($elapsed,1)) min -> $ForgeJson"
+} else {
+    Step "Skipping eval (--SkipEval)"
+}
+
+# ══════════════════════════════════════════════════════════════════════
+# STEP 4 — Compare results
+# ══════════════════════════════════════════════════════════════════════
+Banner "Step 4/4 — Comparing results"
+
+if (-not (Test-Path $BaselineJson)) {
+    Fail "Baseline result not found: $BaselineJson"
+    exit 1
+}
+if (-not (Test-Path $ForgeJson)) {
+    Fail "Forge result not found: $ForgeJson"
+    exit 1
+}
+
+python scripts/compare_eval.py `
+    --baseline  $BaselineJson `
+    --forge     $ForgeJson `
+    --min-delta $MinDelta `
+    --alpha     $Alpha `
+    --json-out  $CompareJson
+
+$exitCode = $LASTEXITCODE
+
+# ── Final summary ──────────────────────────────────────────────────────
+$totalMin = [math]::Round(((Get-Date) - $StartTime).TotalMinutes, 1)
+Banner "Benchmark Complete"
+Write-Host "  Total wall time : $totalMin min"
+Write-Host "  Baseline JSON   : $BaselineJson"
+Write-Host "  Forge JSON      : $ForgeJson"
+Write-Host "  Compare JSON    : $CompareJson"
+Write-Host ""
+
+if ($exitCode -eq 0) {
+    Ok "PASSED — Forge model meets the benchmark threshold."
+    Write-Host ""
+    Write-Host "  Next steps:" -ForegroundColor Cyan
+    Write-Host "    git add results/eval-baseline.json results/eval-forge.json results/compare-result.json"
+    Write-Host "    git commit -m 'results: forge-vs-synthetic benchmark run'"
+    Write-Host "    git push"
+} else {
+    Fail "FAILED — Forge model did not meet the benchmark threshold."
+    Write-Host "  Check $CompareJson for details." -ForegroundColor Yellow
+}
+
+Write-Host ""
+exit $exitCode