diff --git a/SAC_LSTM_Bot/sac_train.sh b/SAC_LSTM_Bot/sac_train.sh
index 704b672..83f7331 100755
--- a/SAC_LSTM_Bot/sac_train.sh
+++ b/SAC_LSTM_Bot/sac_train.sh
@@ -5,7 +5,8 @@
 # owns server lifecycle, opponent connection and dead-bot liveness detection
 # through weights/round_counter.txt), samples opponents by weight per chunk,
 # runs deterministic evaluation (SACLSTM_EVAL_MODE=1) every N chunks, and keeps
-# the best checkpoint (weights/sac_best.zip) by eval win rate.
+# the best checkpoint (weights/sac_best.zip) by a moving-average composite over
+# the eval opponent set (campaign v2 lever 1, #59).
 #
 # Config (env vars):
 #   SAC_OPPONENTS     "Name:weight,Name:weight,..."  (default below)
@@ -13,7 +14,9 @@
 #   SAC_CHUNK_SIZE    rounds per RunTraining battle    (default 10)
 #   SAC_EVAL_INTERVAL eval every N chunks              (default 2)
 #   SAC_EVAL_ROUNDS   rounds per evaluation battle     (default 10)
-#   SAC_EVAL_OPPONENT fixed eval opponent              (default first opponent)
+#   SAC_EVAL_OPPONENTS comma-separated eval set       (default Corners,Crazy,Target)
+#                     — each cycle evaluates EVERY one; results all land in
+#                       eval_log.jsonl (lines carry "opponent":"Name")
 #   SAC_MAX_CRASHES   consecutive crashes before abort (default 5)
 #   SAC_LOG_FILE / SAC_EVAL_LOG_FILE                    (JSON-lines logs)
 #   SACLSTM_*         passed through to the bot (UTD_RATIO, BATCH_SIZE, ...)
@@ -38,7 +41,8 @@ TOTAL_ROUNDS="${SAC_TOTAL_ROUNDS:-100}"
 CHUNK_SIZE="${SAC_CHUNK_SIZE:-10}"
 EVAL_INTERVAL="${SAC_EVAL_INTERVAL:-2}"
 EVAL_ROUNDS="${SAC_EVAL_ROUNDS:-10}"
-EVAL_OPPONENT="${SAC_EVAL_OPPONENT:-${OPPONENTS%%:*}}"
+EVAL_OPPONENTS="${SAC_EVAL_OPPONENTS:-Corners,Crazy,Target}"
+MA_WINDOW=5   # lever 1 (#59): per-opponent moving average over last N evals
 MAX_CRASHES="${SAC_MAX_CRASHES:-5}"
 LOG_FILE="${SAC_LOG_FILE:-$SCRIPT_DIR/training_log.jsonl}"
 EVAL_LOG_FILE="${SAC_EVAL_LOG_FILE:-$SCRIPT_DIR/eval_log.jsonl}"
@@ -46,7 +50,7 @@ CLASSES_DIR="/tmp/opencode/sac_train_classes"
 
 echo "=== SAC_LSTM_Bot training harness ==="
 echo "Opponents: $OPPONENTS | budget: $TOTAL_ROUNDS rounds in chunks of $CHUNK_SIZE"
-echo "Eval: every $EVAL_INTERVAL chunks, $EVAL_ROUNDS rounds vs $EVAL_OPPONENT"
+echo "Eval: every $EVAL_INTERVAL chunks, $EVAL_ROUNDS rounds vs [$EVAL_OPPONENTS], MA-$MA_WINDOW composite best-gating"
 echo "Weights: $SACLSTM_WEIGHTS_PATH"
 
 # ── compile bot + java runner ─────────────────────────────────────────────────
@@ -76,29 +80,60 @@ run_battle() {  # $1=opponent $2=rounds $3=log file
   PPOB_LOG_FILE="$3" java -cp "$CLASSES_DIR:$JAR" RunTraining "$1" "$2"
 }
 
+# ── Lever 1 (#59): eval rotation + MA best-gating ─────────────────────────────
+# best_score.txt FORMAT CHANGE: it used to store the single-opponent integer
+# win rate (%); that semantics is retired. It now stores the COMPOSITE score —
+# the mean over SAC_EVAL_OPPONENTS of each opponent's moving average (last
+# MA_WINDOW eval win rates, %). sac_best.zip is rewritten only when the
+# composite strictly improves.
+ma_hist_file() { echo "$WEIGHTS_DIR/ma_history_$1.txt"; }
+
+composite_of() {  # reads one "w w w ..." history line per opponent on stdin
+  awk -v W="$MA_WINDOW" '
+    NF > 0 { n=NF; k=(n>W)?W:n; s=0; for(j=n-k+1;j<=n;j++) s+=$j; tot+=s/k; c++ }
+    END { if (c>0) printf "%.4f", tot/c; else print "-1" }'
+}
+
 eval_checkpoint() {
-  local tmp="$EVAL_LOG_FILE.tmp" wins rounds wr best
+  # ponytail: opponent names are split by whitespace — fine for Tank Royale bot
+  # names (no spaces); switch to a mapfile IFS=',\n' read if that ever changes.
+  local opps=(${EVAL_OPPONENTS//,/ })
+  local tmp="$EVAL_LOG_FILE.tmp" otmp opp wins rounds wr composite best
   : > "$tmp"
-  echo ">>> [eval] $EVAL_ROUNDS deterministic rounds vs $EVAL_OPPONENT"
-  if ! SACLSTM_EVAL_MODE=1 run_battle "$EVAL_OPPONENT" "$EVAL_ROUNDS" "$tmp"; then
-    rm -f "$tmp"
-    echo ">>> [eval] crashed — keeping previous best"
-    return 0
-  fi
+  for opp in "${opps[@]}"; do
+    otmp="$EVAL_LOG_FILE.$opp.tmp"
+    : > "$otmp"
+    echo ">>> [eval] $EVAL_ROUNDS deterministic rounds vs $opp"
+    if ! SACLSTM_EVAL_MODE=1 run_battle "$opp" "$EVAL_ROUNDS" "$otmp"; then
+      rm -f "$otmp" "$tmp"
+      echo ">>> [eval] crashed vs $opp — keeping previous best"
+      return 0
+    fi
+    wins=$(grep -c '"win":true' "$otmp" || true)
+    rounds=$(grep -c '"type":"game"' "$otmp" || true)
+    if (( rounds == 0 )); then
+      rm -f "$otmp" "$tmp"
+      echo ">>> [eval] no results vs $opp — keeping previous best"
+      return 0
+    fi
+    wr=$(( 100 * wins / rounds ))
+    echo ">>> [eval] win rate: $wins/$rounds ($wr%) vs $opp"
+    cat "$otmp" >> "$tmp"; rm -f "$otmp"
+    # Per-opponent history: append this cycle's win rate, keep last MA_WINDOW.
+    printf '%s\n' "$(cat "$(ma_hist_file "$opp")" 2>/dev/null)" "$wr" \
+      | tail -n "$MA_WINDOW" | tr '\n' ' ' > "$(ma_hist_file "$opp")"
+  done
   mv "$tmp" "$EVAL_LOG_FILE"
-  wins=$(grep -c '"win":true' "$EVAL_LOG_FILE" || true)
-  rounds=$(grep -c '"type":"game"' "$EVAL_LOG_FILE" || true)
-  (( rounds == 0 )) && { echo ">>> [eval] no results"; return 0; }
-  wr=$(( 100 * wins / rounds ))
-  echo ">>> [eval] win rate: $wins/$rounds ($wr%) vs $EVAL_OPPONENT"
+  composite=$(for opp in "${opps[@]}"; do cat "$(ma_hist_file "$opp")"; echo; done | composite_of)
   # ponytail: best-score state is a plain file next to the checkpoint; survives
   # harness restarts, no lock needed (single harness instance assumed).
-  best=-1
-  [ -f "$WEIGHTS_DIR/best_score.txt" ] && best=$(cat "$WEIGHTS_DIR/best_score.txt")
-  if (( wr > best )) && [ -f "$SACLSTM_WEIGHTS_PATH" ]; then
-    echo "$wr" > "$WEIGHTS_DIR/best_score.txt"
+  best=$(cat "$WEIGHTS_DIR/best_score.txt" 2>/dev/null)
+  [ -z "$best" ] && best=-1
+  if awk -v a="$composite" -v b="$best" 'BEGIN{exit !(a+0 > b+0)}' \
+     && [ -f "$SACLSTM_WEIGHTS_PATH" ]; then
+    echo "$composite" > "$WEIGHTS_DIR/best_score.txt"
     cp "$SACLSTM_WEIGHTS_PATH" "$WEIGHTS_DIR/sac_best.zip"
-    echo ">>> [eval] new best ($wr%) -> sac_best.zip"
+    echo ">>> [eval] new best composite ($composite) -> sac_best.zip"
   fi
 }
 
@@ -134,5 +169,5 @@ echo ">>> training complete: $NUM_CHUNKS chunks. Logs:"
 echo "    training: $LOG_FILE"
 echo "    eval:     $EVAL_LOG_FILE"
 [ -f "$WEIGHTS_DIR/sac_best.zip" ] && \
-  echo "    best:     $WEIGHTS_DIR/sac_best.zip ($(cat "$WEIGHTS_DIR/best_score.txt")%)"
+  echo "    best:     $WEIGHTS_DIR/sac_best.zip (composite $(cat "$WEIGHTS_DIR/best_score.txt"))"
 exit 0
diff --git a/SAC_LSTM_Bot/src/SAC_LSTM_Bot/integration.nim b/SAC_LSTM_Bot/src/SAC_LSTM_Bot/integration.nim
index aa9102c..62a620e 100644
--- a/SAC_LSTM_Bot/src/SAC_LSTM_Bot/integration.nim
+++ b/SAC_LSTM_Bot/src/SAC_LSTM_Bot/integration.nim
@@ -12,7 +12,7 @@
 ## Decisions Q1–Q14: Gitea #48.
 
 import arraymancer except Linear
-import std/[locks, os, math, random, strutils]
+import std/[locks, os, math, random, strutils, times]
 import tankroyale_botapi   # getBotName (#49 name-based opponent identity)
 import SAC_LSTM_Bot/network
 import SAC_LSTM_Bot/state        # STATE_DIM
@@ -216,8 +216,18 @@ proc pullWeights*(myVersion: var int; hidden: var int;
     hidden = gSharedSnap.hiddenDim
   true
 
+proc evalModeActive*(): bool {.inline.} =
+  ## Lever 4 (#59): the harness's deterministic eval battles already run the bot
+  ## with SACLSTM_EVAL_MODE=1 (sac_train.sh eval_checkpoint, mechanism from #49).
+  ## While set, eval ticks must NOT feed the trainer — transitions would pollute
+  ## the replay buffer with eval-only data and trigger gradient updates.
+  getEnv("SACLSTM_EVAL_MODE") == "1"
+
 proc sendTrainingMsg*(msg: TrainingMsg): bool {.inline.} =
   ## Bot-side enqueue (cap-256, drops on overflow per Q10). Thread-safe.
+  ## Lever 4 (#59): fully suppressed in eval mode — NewBattle drops too, so an
+  ## eval battle can neither add transitions nor clear/retarget the buffer.
+  if evalModeActive(): return false
   gTrainChan.trySend(msg)
 
 # ── Training state (testable without threads) ─────────────────────────────────
@@ -256,6 +266,41 @@ proc initTrainState*(initial: FullSnap): TrainState =
   result.lastEnemyKey = ""
   result.nextSave   = getSaveInterval()
 
+# ── Training-loss metrics (campaign v2 lever 3, #59) ──────────────────────────
+
+proc metricsFilePath*(): string =
+  ## Sits next to the weights dir's parent: SAC_LSTM_Bot/training_metrics.jsonl
+  ## under the #49 harness (weights live in SAC_LSTM_Bot/weights/).
+  getWeightsPath().parentDir.parentDir / "training_metrics.jsonl"
+
+proc metricsLine*(epoch: float64; stepCount, bufferLen, drained, gradSteps: int;
+                  m: SACMetrics): string =
+  ## One JSONL line with exactly the scalars SACTrainer.sacUpdate exposes
+  ## (#59 lever 3 — SACMetrics was already returned, no trainer change needed):
+  ## losses/alpha averaged over this pass's gradient steps, buffer size from
+  ## replay_buffer.len, cumulative step count and drained transition count.
+  "{\"epoch\":" & $epoch &
+    ",\"steps\":" & $stepCount &
+    ",\"buffer_size\":" & $bufferLen &
+    ",\"drained\":" & $drained &
+    ",\"grad_steps\":" & $gradSteps &
+    ",\"critic_loss\":" & $m.criticLoss &
+    ",\"actor_loss\":" & $m.actorLoss &
+    ",\"alpha_loss\":" & $m.alphaLoss &
+    ",\"alpha\":" & $m.alpha & "}"
+
+proc appendMetricsLine(st: TrainState; drained, gradSteps: int; m: SACMetrics) =
+  ## Lever 3 (#59): one append per trainPass (never per gradient step). Open,
+  ## write, close — cheap and crash-tolerant; a metrics failure never kills
+  ## training.
+  try:
+    let f = open(metricsFilePath(), fmAppend)
+    f.writeLine(metricsLine(epochTime(), st.stepCount, st.buf.len,
+                            drained, gradSteps, m))
+    f.close()
+  except CatchableError:
+    discard
+
 proc handleTrainingMsg*(st: var TrainState; msg: TrainingMsg): bool =
   ## Process one message. Returns false for Shutdown (caller stops).
   ## Tensors are born HERE from the message's plain arrays — training thread only.
@@ -284,11 +329,16 @@ proc trainPass*(st: var TrainState; drained: int) =
   if drained <= 0 or not st.buf.canSample:
     return
   let steps = drained * getUtdRatio()   # Q2
+  var gradSteps = 0
+  var sumCritic, sumActor, sumAlphaLoss, sumAlpha = 0.0'f32
   for i in 1 .. steps:
     let seqs = st.buf.sampleSequences(getBatchSize())
     if seqs.len == 0:
       break
-    discard sacUpdate(st.trainer, seqs)
+    let m = sacUpdate(st.trainer, seqs)
+    sumCritic += m.criticLoss; sumActor += m.actorLoss
+    sumAlphaLoss += m.alphaLoss; sumAlpha += m.alpha
+    inc gradSteps
     inc st.stepCount
     # Save check INSIDE the step loop (#56 launch finding): at production sizes
     # (hidden 256 ⇒ ~1 s/step) a drain burst queues minutes of steps; checking
@@ -299,6 +349,13 @@ proc trainPass*(st: var TrainState; drained: int) =
       st.nextSave += getSaveInterval()
       var full = packFull(st.trainer)
       discard gSaveChan.trySend(move(full))   # cap-1: drop if I/O thread is busy (Q5)
+  if gradSteps > 0:
+    # Lever 3 (#59): one metrics line per pass, losses averaged over its steps.
+    appendMetricsLine(st, drained, gradSteps, SACMetrics(
+      criticLoss: sumCritic / gradSteps.float32,
+      actorLoss:  sumActor  / gradSteps.float32,
+      alphaLoss:  sumAlphaLoss / gradSteps.float32,
+      alpha:      sumAlpha / gradSteps.float32))
   # Publish latest actor (Q7): in-place write under the lock, bump version.
   withLock(gWeightLock):
     assert gSharedSnap.hiddenDim == st.trainer.actor.hiddenDim,
@@ -382,6 +439,10 @@ proc initIntegration*() =
   initLock(gWeightLock)
   gTrainChan.open(256)   # Q10 cap-256
   gSaveChan.open(1)      # Q5 cap-1
+  # Lever 4 (#59): one-time visibility for the suppression gate (see
+  # sendTrainingMsg) — the eval bot trains nothing by design.
+  if evalModeActive():
+    stderr.writeLine "[sac] SACLSTM_EVAL_MODE=1 — training input suppressed (lever 4, #59)"
   createThread(gTrainingThread, trainingThreadEntry)
   createThread(gIoThread, ioThreadEntry)
 
diff --git a/SAC_LSTM_Bot/tests/test_integration.nim b/SAC_LSTM_Bot/tests/test_integration.nim
index 5d9c11e..f30aa13 100644
--- a/SAC_LSTM_Bot/tests/test_integration.nim
+++ b/SAC_LSTM_Bot/tests/test_integration.nim
@@ -122,3 +122,29 @@ block:
   assert alpha == t0.alpha()
   discard tc1
   echo "PASS flat snapshot pack/unpack round-trip"
+
+# ── 5. Lever 3 (#59): metricsLine emits exactly the exposed trainer scalars ───
+block:
+  let line = metricsLine(1787394115.123, 42, 500, 20, 20,
+    SACMetrics(criticLoss: 0.5'f32, actorLoss: -1.5'f32,
+               alphaLoss: 0.25'f32, alpha: 2.0'f32))
+  let j = parseJson(line)   # throws on malformed JSONL
+  assert j["steps"].getInt() == 42 and j["buffer_size"].getInt() == 500
+  assert j["drained"].getInt() == 20 and j["grad_steps"].getInt() == 20
+  assert abs(j["critic_loss"].getFloat() - 0.5) < 1e-3
+  assert abs(j["actor_loss"].getFloat() + 1.5) < 1e-3
+  assert abs(j["alpha_loss"].getFloat() - 0.25) < 1e-3
+  assert abs(j["alpha"].getFloat() - 2.0) < 1e-3
+  assert j["epoch"].getFloat() > 1e9
+  echo "PASS metricsLine JSONL scalars"
+
+# ── 6. Lever 4 (#59): SACLSTM_EVAL_MODE=1 suppresses training input ───────────
+block:
+  putEnv("SACLSTM_EVAL_MODE", "1")
+  # Gate fires before any channel traffic: false = dropped, nothing enqueued.
+  assert not sendTrainingMsg(TrainingMsg(kind: tmkTransition)),
+    "eval mode must drop transitions"
+  assert not sendTrainingMsg(TrainingMsg(kind: tmkNewBattle, enemyId: 7)),
+    "eval mode must drop NewBattle (no buffer clears from eval)"
+  delEnv("SACLSTM_EVAL_MODE")
+  echo "PASS eval-mode training-input suppression"