C4 (768x4 + rollout=True, 150 iter) result: 0/300 natural wins, score
avg -85 to -97 vs three heuristic opponents. Bigger network alone did
not produce wins; PA shifted up to 0.23-0.25 (similar to c3 without
rollout) but agent still loses every natural-end game.
Capacity hypothesis rejected: 2.5x more params (~2M vs ~800k) did not
break the loss pattern. Score average actually slightly worse than
512x3 baseline. So the bottleneck is not network capacity.
Going to the long-run experiment: AlphaZero-correct setup with the
network value loop closed. use_rollout_value=false means leaf Q comes
from network value head. Training signal: network value learns from
actual game outcomes; MCTS uses those values to pick actions; better
actions produce better outcomes; cycle closes.
100 iter previously gave essentially the same result as rollout=true
(comparing c3 to trapfix baseline). Both are too early in the AlphaZero
training curve. Standard AlphaZero papers train 1000s of iterations.
Going long: 1000 iter with the current config. Self-play ~9s/iter
without rollout, total wall ~150 min for the train phase.
Plotting strategy: at iter 200, 500, 1000, run 100-game standalone eval
and generate analyze.py plots to visualize trajectory.
Network kept at 768x4 since bigger capacity does not actively hurt.
c3 showed use_rollout_value=false alone is not the fix: without the
heuristic rollout safety net the random-init network value gives bad
MCTS Q early on, the agent plays more (PA 0.10 -> 0.22+) but eats more
-20 expedition penalties (score worsened from -57 to -97 avg).
Mathematical intuition: in Lost Cities, opening an expedition is a
20-point commitment. Break-even requires rank-sum × (handshakes+1) >= 20.
The model has to learn:
- which colors to open (based on hand handshake/high-rank holdings)
- when to commit vs discard
- card-ordering constraints (ascending only)
This is a moderately rich value function. 512x3 (~800k params, ~290
input dim) might be undersized. Test capacity hypothesis with 768x4
(~2M params) while keeping the rollout safety net so MCTS Q stays
competent.
Other params from c1 kept: c_puct=5, virtual_loss=5, dirichlet
α=0.3/ε=0.4, parallel_simulations=64, n_simulations=50.
Codex deep diagnosis surfaced two real issues in our MCTS pipeline:
1. mcts.pyx::search() hardcoded prepare_simulation_batch(state, traverser, 1)
instead of respecting MctsConfig.parallel_simulations. Standalone evals
(eval_checkpoint, evaluate_with_mcts sequential path, eval_worker) all
use this entry point, so all eval-time MCTS was running 1 sim per batch
regardless of the configured 64. Training was unaffected because it
goes through interleaved_self_play._run_search_jobs which respects the
config. Fix uses min(config.parallel_simulations, sims - completed).
2. use_rollout_value defaulted to True (config.py) but was never set in
the YAML. With this, _expand_with_prior returns the heuristic rollout
value and discards network_value, so the network value head is trained
from final game scores but its outputs are never fed back into MCTS
backups. This explains why mcts/value_prediction_error stays high
despite training -- learning the value head produces no behavioral
change because MCTS never reads it.
Now setting use_rollout_value=false in default.yaml so the network value
head closes the loop. Combined with the existing Dirichlet root noise +
heuristic rollout removal, this should give the network's value learning
actual leverage on action selection.
Also: updated test_search_visit_counts_match_with_parallel_simulations
to test the correct invariant (legal-action set match + total visit
count near n_sims) rather than literal visit-count equality, which was
only true under the previous bug.
Tests: 19/19 passing.
50-iter sweep on default.yaml with stronger MCTS exploration:
- c_puct: 3.0 -> 5.0 (UCB weight, more exploration of low-prior actions)
- root_dirichlet_epsilon: 0.25 -> 0.4 (more noise injected at root prior)
Standalone eval at iter 50 (30 games/opponent, all natural-end, timeouts=0):
- vs heuristic-balanced: W=0/30 S=-70.5 (PA 0.15)
- vs heuristic-aggressive: W=2/30 S=-65.1 (PA 0.14) [+10, +4]
- vs heuristic-cautious: W=1/30 S=-48.0 (PA 0.14) [+2]
3 natural-end wins vs prev trapfix baseline iter 44 (which had 0 natural
wins + 1 timeout-tie). Stall trap fixed remains true (timeouts=0 in c1).
Trade-off observed: more exploration -> higher variance. Score avg vs
cautious worsened (-32 -> -48), but win events appeared. For the
non-terminal-win objective, exploration win > score-avg loss.
Next: commit to long run (300 iter) with these params before tuning more.
Trap diagnosis: agent learned to stall (avoid opening expeditions, draw
from discard pile to extend deck) until max_steps timeout, then squeak by
on opponents' negative scores. All eval wins were from timeouts; agent
never won a naturally-terminating game. Self-play reinforced this because
timeout games still got a positive value target.
Fixes (no algorithm change, all MCTS hyperparameters or signal shaping):
- Dirichlet noise at root prior (AlphaZero standard, was missing):
mcts.pyx `_expand_with_prior` takes `is_root` flag; root expansion
mixes prior with Dirichlet(α). Callers in interleaved_self_play and
the internal evaluate_and_backup pass `not item.path`.
- Default config strengthens exploration on the 50-sim batched search:
c_puct 1.5 -> 3.0, virtual_loss_value 1.0 -> 5.0, plus new
root_dirichlet_alpha=0.3 / root_dirichlet_epsilon=0.25.
- Self-play timeout signal zeroed: `_finalize_context` sets v_target=0
if context.state is not terminal. Stops the network from learning
"stall = positive value".
New standalone evaluator:
- `lost-cities-ismcts eval` subcommand (eval_checkpoint.py): loads a
checkpoint, runs N games per opponent across a parallel pool, reports
win/score with 95% CIs plus per-game logging via --verbose. Defaults
cover heuristic-balanced/aggressive/cautious (rollout policy isn't in
the training-eval opponent list, so this is the natural way to compare
the trained policy against its rollout target).
Tests (19) still pass; .so rebuilt.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Key changes for ISMCTS speed and correctness:
- Cython port: HeuristicBot helpers (`heuristic_cy.pyx` + new `.pxd`) and
ISMCTS searcher (`mcts.pyx`) now run as cdef. Both share a fast
unified-action path through GameState's C interface to avoid Python
round-trips on hot rollout/tree-walk paths.
- Multi-process self-play and eval: `workers.py`, `eval_worker.py`,
`interleaved_self_play.py`, plus trainer wiring with ProcessPoolExecutor
+ spawn context. Eval inside `evaluate.py` is parallel per opponent.
- ISMCTS-specific eval (`evaluate.py`) runs MCTS at decision time so the
metric matches deploy mode; `evaluation.eval_with_mcts` flag preserves
backwards-compatible policy-only eval when needed.
- Trainer logs progress per phase (self-play start/done, eval per
opponent), and value loss is now scaled by `value_scale` so policy and
value losses sit on comparable magnitudes.
- Compact info-set key (`info_set.py`) using packed-struct format and
child-key reuse during MCTS descent to cut per-step canonicalization.
Tests: 19 ISMCTS suite passing, including parity (Cython-vs-Python
sequential, batched-vs-sequential visit counts, push/pop round-trip).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Implements a proof-of-concept single-observer IS-MCTS trainer with AlphaZero-style policy/value network, determinization, replay, self-play, CLI configs, and focused tests. Mini acceptance run reaches positive random eval while keeping play_action_rate above the Deep CFR trap threshold.
Tests: uv run python -m pytest tests/games/classic/ismcts/ -x; uv run python -m pytest tests/games/classic/test_deep_cfr_trainer.py -x; uv run lost-cities-ismcts train --config configs/ismcts/mini.yaml
Three coordinated hygiene changes; none target the diagnosed
selection-bias bottleneck. They make the codebase honestly reflect the
pure-self-play stance and reduce dashboard noise.
Bot rename (drop the unhelpful safe_ prefix; suffixes describe behaviour):
- safe_heuristic_loose -> heuristic_aggressive
- safe_heuristic -> heuristic_balanced
- safe_heuristic_strict -> heuristic_cautious
- noisy_safe -> heuristic_noisy
- passive_discard -> discard_only
Class renames in bots/: SafeHeuristicBot -> HeuristicBot,
SafeHeuristicParams -> HeuristicParams, PassiveDiscardBot -> DiscardOnlyBot,
plus loose/strict parameter constants. Backwards compatibility was dropped
intentionally per user instruction; no aliases. Active configs, docs,
scripts, tests updated. Archive directories (configs/archive,
docs/archive, runs/archive) left intact and may still reference old
names per their read-only policy. The src/.../bots/passive.py module was
renamed to discard_only.py via git mv.
Analyze plot curation (deep_cfr/analyze.py):
- Added analysis_00_core.png as the canonical daily dashboard with 10
heuristic-free metrics (loss/{advantage,strategy}; vs heuristic_cautious:
avg_score_diff0, win_rate0, avg_opened_colors, positive_expedition_rate,
bonus_expedition_rate, score_per_opened_color, policy_entropy; vs random:
win_rate0).
- Removed analysis_05_open_quality.png (bad/weak/good open rates,
recoverable score) and analysis_07_calibration.png (calibration gap,
recoverable mean) - both relied on the heuristic recoverable_score
classifier already dropped from inputs.
- Removed SELECTIVITY_PLOTS and plot_selectivity (heuristic-laden).
- SUMMARY_EVAL_METRICS no longer includes bad_open_rate or
calibration_gap.
- PlotSpec gained an opponents allowlist so the new core section can pin
a specific opponent per panel without restructuring plot_section.
Tiered evaluation cadence (EvaluationConfig):
- Added extended_opponents and extended_eval_every (default 0 = disabled).
- opponents_for_iteration(iteration) returns the core list every
eval_every and appends extended_opponents (de-duplicated) when
iteration is also a multiple of extended_eval_every.
- default.yaml now uses 3 core opponents (random, discard_only,
heuristic_cautious) every 5 iterations and 3 extended opponents
(heuristic_balanced, heuristic_aggressive, heuristic_noisy) every 50
iterations. random is the floor sanity. discard_only is the
zero-pit detector / absolute-score reference (its score is always 0,
so eval/discard_only/avg_score_diff0 directly equals the model's raw
average score). heuristic_cautious is the ceiling and the
archive-comparable benchmark used in the prior diagnostic sections.
Net eval cost reduction: roughly 50% (3 opponents x every 5 iter, plus
6 opponents x every 50 iter, vs the prior 6 x every 5).
Documented in docs/plans/deep-cfr-selectivity.md section 9.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The interleaved traversal scheduler's _regret_matching was hard-coded to
spread fallback policy uniformly across legal actions, regardless of the
configured regret_matching.all_negative_fallback. default.yaml has
shipped with all_negative_fallback: argmax_tiebreak since 618d5f8 based
on the 20-iter audit + 1000-iter empirical comparison in
docs/archive/deep-cfr-regret-fallback-audit-2026-05-07.md, but the
default scheduler was switched to interleaved in 09bbe7c, after which
the configured fallback mode silently no-op'd.
_regret_matching now takes fallback_mode and concentrates policy mass on
the lowest-index tied action when "argmax_tiebreak". Tiebreak is
deterministic; the Cython recursive traverser randomises ties using its
per-traverser RNG, which the batched policy does not have. Behaviour
matches the spirit of the recursive path (concentrate on best, do not
dilute uniformly).
Plumbed through BatchedPolicy, InterleavedTraversalConfig,
run_interleaved_traversal_batch, trainer.py, workers.py, and the
analyze_first_open_targets.py caller. Two unit tests added.
Also bumps default.yaml outcome_sampling_epsilon 0.2 -> 0.05. The
200-iter sweep in docs/plans/deep-cfr-selectivity.md section 1 showed
0.05 produced the best short-run safe_heuristic_strict score diff
(-40.01 vs -57.87 for 0.20). Recent experiments already used 0.05; the
default now matches actual experimental practice.
Neither change targets the diagnosed selection-bias bottleneck. They
align config intent with scheduler behaviour and make the default config
reproduce known-best knob settings out of the box.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Implements the central inference server pattern: a dedicated GPU
process owns advantage/strategy/league networks, batches policy
requests across traversal workers via shared-memory tensor pool, and
returns logits. Workers route forward calls through InferenceClient /
NetworkProxy when traversal.inference_backend == "server".
Default remains traversal.inference_backend: local. The server
backend regresses iter time ~3.8× on the inspected default config
(small-model dispatch + sync-blocking traversal capping realized
batch at ~num_workers=8 instead of the bs=64-256 needed to amortize
IPC overhead). Keeping the implementation behind the flag lets us
re-enable when (a) model size grows, (b) per-worker interleaved
traversal lands, or (c) eval becomes dominant — see
docs/performance.md "Option A Bench Result and Structural Ceiling"
for the full diagnosis.
Plumbing included:
- inference_buffers.py: shared-memory tensor pool with slot
management.
- inference_client.py: per-worker client + NetworkProxy adapter for
the existing traversal.pyx call sites.
- inference_server.py: spawn-context server process with
batch-window aggregation, weight sync, shutdown sentinel.
- bench_inference_backend.py: A/B between local and server backends
with eval/checkpoint disabled.
- test_inference_server.py: round-trip and integration tests.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The avg-strategy 1000iter file (with the recent +traversals/+LR/+LCFR
changes) is the canonical "best-known" config. Renamed it to
default.yaml so users start from a single, obvious entry point and
override one field per ablation via --set. Other 12 configs moved to
configs/archive/ — kept for historical reproduction, not for active use.
- configs/deep_cfr/{default.yaml, smoke.yaml} are the only active configs
- experiment_name shortened to "deep-cfr-default" (was a long mouthful)
- AGENTS.md examples and Project Layout section rewritten around
default.yaml; ablation example shows the override-one-field pattern
- Tests pointed at the archived slot-playability config for the legacy
reproduction assertions
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Drop checkpoint.directory from config — config defines what an experiment
is, not where its outputs go. The CLI now computes the run directory from
run.experiment_name plus a timestamp, defaulting to runs/tmp/ for
throwaway runs and runs/ when --keep is passed.
- Remove CheckpointConfig.directory and DeepCFRConfig.checkpoint_path
- DeepCFRTrainer takes run_dir: Path explicitly
- CLI: add --keep boolean; --resume requires an explicit path (no shortcut)
- Auto path: runs/[tmp/]<YYYY-MM-DD_HHMMSS>_<experiment_name-kebab>/
- Rename 13 configs to kebab-case; strip directory: lines; kebab their
experiment_name values
- Rewrite AGENTS.md training/run sections; document
archive/tmp/<flat> layout, --keep, kebab-case scope
- Update tests for new run_dir flow and dropped --resume shortcut
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Remove legacy aliases, rename max_hours to max_minutes, collapse the
four checkpoint save flags into save_every + save_latest, and change
defaults to safer values (opponent_policy=self_play_league,
device=auto, eval_every=50, max_depth=null). Migrate all archived
yaml configs and tests to the new schema.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Strategy network (학습 중인 average policy)를 traversal opponent로 사용하는
새 옵션 추가. Deep CFR 이론적 수렴이 average strategy에 대한 보장이라는
점에 착안 — opponent_policy=network의 발산 문제를 완화할 수 있는지 실증.
구현:
- config: opponent_policy validator에 average_strategy 추가
- traversal.pyx: opponent_policy_id=3, strategy_network 인자, softmax 기반
policy 도출 (_policy_from_strategy_network)
- workers.py: TraversalWorkerBatch에 strategy_network state_dict 추가
- trainer.py: 직렬/병렬 traversal call에 strategy_network 전달
- 1000-iter 실험 config 추가 (opponent_policy=network와 동일 hyperparam)
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
opponent_policy=network 설정으로 1000-iter 실험 두 개 (512x3, 1024x4)를
돌린 결과 두 실험 모두 policy collapse가 발생함을 확인. 큰 capacity는
plateau를 늘리지만 발산 자체를 막지 못함. 향후 학습은 self_play_league
기본값을 유지할 것을 권고.
- 실험에 사용한 config 두 개 추가
- 발견 분석 문서 추가 (원인, 비교, 권고)
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
- Add deep_cfr_color_shared_512x3.yaml: color_shared without attention
- Add deep_cfr_color_shared_attention_512x3.yaml: color_shared with 2-layer attention
- Both use 512 hidden size and 3 MLP layers
- Configs are ready for experimental training runs
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
coolguy
