docs: cs-bug scope audit (preflop-only vs broader) + perf claim re-validation#161
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…lidation Audit of `cs = contributions - initial_contributions` bug pattern (PR #159 context) across all subgame solver entry points. Findings: - Bug scope: PARTIAL. Same `State::initial` pattern in TWO solvers (`preflop_rvr` AND `preflop`), but Python `HUNLConfig.__post_init__` blocks the trigger combination (`Preflop` + `initial_contributions != [0,0]`). Reachable only via Rust-direct callers bypassing Python. - Postflop solvers (`solve_hunl_postflop`, `solve_range_vs_range_*`, exploit BR-walk) are NOT affected — they use the correct postflop branch at `crates/cfr_core/src/hunl.rs:318`. - All shipped perf claims (#114, #139, #150, #157) STAND. Every bench either uses `initial_contributions=[0,0]` (degenerate-subtraction-safe) or the unaffected postflop solver. - Recommendation: fix `PreflopRvrState::initial` (preflop_rvr.rs:229-251) + `HUNLState::initial_preflop` (hunl.rs:382-414) to honor `config.initial_contributions`, and add a Rust-side `HUNLConfig::validate()` mirroring Python's `__post_init__`. No engine code touched — surface-only audit. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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…ns (#67) (#165) Root cause documented in PR #159 and audited in PR #161: both `PreflopRvrState::initial` and `HUNLState::initial_preflop` unconditionally set `contributions=[SB+ante, BB+ante]` regardless of `config.initial_contributions`. Downstream leaves compute `cs = contributions - initial_contributions`, so a caller passing `initial_contributions=[SB,BB]` with `initial_pot=0` (intending to declare posted blinds) produced `cs=[0,0]` and `pot_total=0` at every leaf — collapsing the preflop Nash to fold-everywhere. Fix: - `State::initial` honors `initial_contributions`: `contribution[i] = max(blind_amount[i], initial_contributions[i])`. Engine-posts-blinds (`[0,0]+pot=0`) and caller-declared-blinds (`[SB+ante,BB+ante]+pot=SB+BB+2*ante`) configs both produce Nash-equivalent strategies (per-leaf payoffs differ only by a constant per-player shift). - Add Rust-side `HUNLConfig::validate()` mirroring `poker_solver/hunl.py:124-176` (defense-in-depth per `feedback_silent_skip_hazard` — PyO3 callers bypass Python's `__post_init__` guard). - Wire `validate()` into `solve_hunl_preflop_rvr` so malformed configs (e.g., `[50,100]+pot=0`) fail loudly instead of returning a degenerate fold-everywhere equilibrium. Tests: - `crates/cfr_core/tests/preflop_initial_contributions.rs` (11 Rust tests): AA-does-not-fold regression, identical-strategies diff-test between both well-formed configs, eight `HUNLConfig::validate()` accept/reject cases, and an entry-point rejection test for the bug-triggering config. - `tests/test_preflop_rvr_diff.py::test_engine_agnostic_to_blind_declaration`: Python-side parametrized variant of the diff-test (max_drift < 1e-4 between the two config shapes through the PyO3 boundary). Existing tests verified clean: - AA-vs-KK closed-form smoke (`preflop_rvr_smoke.rs`) still PASSes. - All 4 `test_preflop_rvr_diff.py` Python diff tests PASS. - `cargo test -p cfr_core --lib`: 75 unit tests PASS. - `cargo clippy --lib --tests`: clean. - `ruff check`: clean. Postflop branch (`hunl.rs:318`) unchanged — it was already correct. Leaf-payoff math unchanged — only `State::initial` and `validate()`. Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Summary
PreflopRvrState::initialhardcoding[SB,BB]while leaves docs = contributions - initial_contributions) extends to other solvers.HUNLState::initial_preflop(crates/cfr_core/src/hunl.rs:382-414) too, but PythonHUNLConfig.__post_init__(poker_solver/hunl.py:146-148) blocks the trigger combination. Postflop solvers are NOT affected (correct postflop branch athunl.rs:318).initial_contributions=[0,0](where the subtraction is degenerate-safe) or the unaffected postflop path.Test plan
crates/cfr_core/src/preflop_rvr.rs:229-251,crates/cfr_core/src/hunl.rs:318, 382-414,crates/cfr_core/benches/preflop_rvr_profile.rs:42-66, etc.)State::initialdispatch against its leaf-utility formulapoker_solver/hunl.py:146-148is the load-bearing safeguardDoc-only PR. Auto-merge OK.
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