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foxhunt/config/ml
jgrusewski 8548d126fd chore(alpha): H=600 DQN smoke verdict — FAIL on rvr (linear Q lock-in)
Phase E.1 Task 12. Stabilized H=600 DQN smoke ran end-to-end on full
500K-snapshot data. All three preconditions PASS but the rvr gate FAILS:

  Q_SPREAD_EMA          = 35.54   ≥ 0.05    PASS
  ACTION_ENTROPY_EMA    = 1.91    ≥ 1.099   PASS
  RETURN_VS_RANDOM_EMA  = -2.58   ≥ 0.0     FAIL  ← policy WORSE than random
  EARLY_Q_MOVEMENT_EMA  = 0.096   ≥ 0.01    PASS

rvr trajectory across 1000 episodes:
  ep   50 | rollout_R= -11049 | rvr = -1.18  (near random)
  ep  200 | rollout_R=  -9620 | rvr = -0.97  (briefly improving)
  ep  600 | rollout_R= -18140 | rvr = -2.03  (degrading)
  ep 1000 | rollout_R= -18272 | rvr = -2.58  (deterministic-bad)

Random baseline at H=600 = -5185 mean, std=4953. Trained policy loses
3.5× worse than random.

Diagnostics performed:
  reward_scale=10000 → rvr=-2.37 (no help)
  alpha_m=0 (vanilla DQN, no Munchausen) → rvr=-2.44 (no help)

Root cause: "first-best-action lock-in" of linear Q + ε-greedy. DQN's
TD update only modifies Q[a] for the TAKEN action; with ε-decay, the
argmax action self-reinforces while other actions' Q stays frozen at
random Xavier init. Random policy samples all 9 uniformly → 11% chance
of "lucky" close-position at any step → exits bad trades. Trained
policy converges deterministic on one bad action → never exits.

Per plan: pivot to NoisyNet (Task 19) — parameter-space noise breaks
the lock-in. Alternative: wire alpha_logit from Phase 1d.3 stacker
(currently hardcoded to 0.0 placeholder) so the policy has actual
directional signal to work with.

Kill-criteria gate worked as designed — correctly flagged that linear
Q + ε-greedy on this env is insufficient without further intervention.

Memory note: project_phase_e1_h600_smoke_verdict.md (full analysis +
hypothesis tree + recommended next steps).
2026-05-15 16:09:28 +02:00
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