coolguyandClaude Opus 4.7 f289997c1c Add Dirichlet root noise + standalone eval CLI, fix self-play stall trap
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>
2026-05-11 05:17:32 +09:00
2026-05-08 16:22:52 +09:00
2026-05-07 15:42:30 +09:00

coolrl-lost-cities

Focused Lost Cities extraction from the legacy coolrl repository.

The current implementation starts with the classic two-player card game:

  • classic 5-expedition rules by default
  • Python/Cython game engine
  • env wrapper
  • random, discard-only, and safe-heuristic bots
  • core rule, scoring, mask, env, canonical-state, bot, and GUI smoke tests

Training code, Deep CFR, learned-policy evaluation, GUI, and web client are intentionally outside the first port.

Development

uv run pytest tests/games/classic
uv run lost-cities-classic

For future GUI work, install the optional GUI dependencies:

uv sync --extra gui

Run the classic pygame GUI:

uv run lost-cities-classic-gui --mode pvc --bot safe-heuristic

The GUI uses the in-process Cython game engine.

Basic Usage

from coolrl_lost_cities.games.classic import GameState, build_bot, classic_config

state = GameState.new_game(classic_config(seed=1))
bot = build_bot("random", seed=1)

while not state.terminal:
    state.apply_action(bot.act(state))

print(state.total_score(0), state.total_score(1))

See classic port notes for the current direction.

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Description
Lost Cities
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