typhoon.git/src/CLAUDE.md, branch master

Fix batch-mode exit code, killer-table backfill collision, impossible QSearch mate-magnitude asserts, MATEMOVE PV display, --command truncation, and test.sh's stale egtbpath.

2026-08-30T02:26:49Z

Several small, independent correctness fixes bundled together since they were all exercised together through today's precommit_check.sh and curated-suite runs: - command.c: batch-mode's "Exhausted input" exit was exit(-1), which truncates to 255 (an 8-bit status) and is indistinguishable from a real crash's nonzero exit. Changed to exit(0) so debug_smoke_test.sh can reliably tell a clean batch run apart from a crash by exit status alone. - dynamic.c: _NewKillerMove's slot[1] backfill from mvNullmoveQuietRefutations[uPly] had no check that the backfilled move differed from the move just placed in slot[0]. When they coincided, both slots held the identical move, silently wasting a killer slot in release builds (ASSERT is a no-op there) and tripping _NewKillerMove's own IS_SAME_MOVE invariant in DEBUG builds. Fixed by skipping the backfill on collision. - search.c: removed two ASSERT(iBestScore > -NMATE) calls in QSearch that encoded an invariant that isn't actually guaranteed -- at an early full-width root iteration, or after aspiration-window widening following repeated fail-highs, an ancestor frame's iAlpha/iBeta can itself already be more extreme than -NMATE with no mate anywhere in the line, so a legitimate fail-low placeholder or fail-high score can land in mate-magnitude territory purely as a window artifact. hash.c's storage path already treats any value <= -NMATE as a sound upper bound regardless of origin, so this was a false invariant, not a caught bug. Also: minor whitespace cleanup, an added ASSERT documenting the futility-margin depth precondition it replaced a redundant runtime check for, and PV/leaf-count bookkeeping on the mate/draw-at-root leaf paths that was previously skipped. - util.c: MATEMOVE sentinel moves weren't handled in PV-to-string conversion, so a PV ending in a detected mate would either display garbage or hit the same-move assert. Added an explicit "<#>" marker. - test.sh: --egtbpath pointed at a nonexistent /egtb/three;/egtb/four; /egtb/five; corrected to /zscratch/egtb, this box's actual EGTB location. - main.c/input.c: --command's initial-command buffer (g_szInitialCommand) was a fixed 256-byte array; strncpy(..., SMALL_STRING_LEN_CHAR - 2) silently truncated any longer --command string, and -- worse -- when the source was long enough not to fit, strncpy doesn't null-terminate the destination, so the immediately-following strcat(..., "\r\n") could read/write past the buffer. Long move-replay command strings used during this session's debugging hit the truncation directly (a ~600 char move list silently cut off mid-token, desyncing the input queue). Changed g_szInitialCommand to a heap allocation sized to the actual input length instead of a fixed cap. - CLAUDE.md: documents the above (this file's own diff is prior session's writeup of these same fixes, committed now alongside the code). All exercised together via precommit_check.sh (self-test suite + DEBUG smoke test against random ecm.ep_ samples) and the sd10/sn5m curated suite sweep run for the eval.c hand-tuning commit just before this one. Co-Authored-By: Claude Sonnet 5 Claude-Session: https://claude.ai/code/session_01M9ZDiJhiUajUxh95mTXCFJ

Dynamic move ordering overhaul: continuation-history, evidence-gated

2026-08-29T22:03:54Z

countermove promotion, retired hung-piece-escape and NumLeftoverMovesToSelect. Full session was built on a "measure the pick, not the game" methodology: aggregate solve counts on curated suites are too noisy to tune move-ordering knobs against, so most decisions here came from per-move fail-high/alpha-raise rates at much larger sample sizes (leftover FH% instrumentation, a zero- selection-budget diagnostic that isolates a single best-of-remaining pick, and evidence-bucket calibration), not solve-count deltas alone. See CLAUDE.md's "Dynamic move ordering experiments" section for the reusable methodology and generate.c's _ScoreAllMoves comment for the resulting ordering hierarchy. Changes: - Added g_ContinuationHistory: same growth/decay math as the existing g_HistoryCounters butterfly table, additionally keyed by the previous move, so its magnitude is self-calibrated rather than a hand-picked constant. Flat, sufficient response across a 256x scale sweep. - Countermove-table matches now get a real GOOD_MOVE-tier promotion (previously the table was write-only, tracked for stats but never read for ordering), but only when the match's own accumulated history+continuation evidence clears COUNTERMOVE_EVIDENCE_THRESHOLD (10,000) -- a raw match with no track record was shown to perform identically to an ordinary leftover (~0.6-0.85% FH), so promoting on match alone would have repeated hung-piece-escape's mistake below. - Retired hung-piece-escape's unconditional GOOD_MOVE-tier promotion. Evidence-calibration showed the overwhelming majority of triggers (a zero-evidence population 250-1000x larger than countermove's) performed at the plain-leftover baseline -- the promotion was mostly free tier- escape treatment for moves that hadn't earned it. Replaced with FLEE_BONUS, a flat same-tier nudge inside SelectBestWithHistory (never escapes GOOD_MOVE/leftover classification, unlike a generation-time promotion) at the magnitude found to plateau a same-tier-nudge sweep. - Retired NumLeftoverMovesToSelect (the depth-indexed budget on how many leftover moves got a full selection scan before falling back to unsorted order). search.c's main move loop now always fully selects -- the leftover pool was shown to contain real, findable signal a bailout budget was discarding for a node-count savings that didn't hold up net- net once measured by solve counts and fail-high rates rather than raw node counts (noisy on small suites independent of this change). - Collapsed leftover-move instrumentation from sorted/raw pairs down to a single set now that "raw" (unsorted fallback) is structurally impossible; kept the countermove evidence-bucket calibration counters (ongoing check that COUNTERMOVE_EVIDENCE_THRESHOLD stays well- calibrated); removed the contested-node A/B harness and hung-piece evidence calibration now that the decisions they were built to inform are made. Net effect on the three curated suites (sd 10): solve counts wash (tied, +1, -1 across ringers/confident/hard), leftover fail-high rate improved consistently on all three (the intended, directly-measured target of this work). Not yet validated beyond sd 10 -- an sn-based run or eval_tune/match_play.py head-to-head gate is the natural next check before leaning on this as a proven strength gain rather than a directionally- sound, sd-10-clean change. Co-Authored-By: Claude Sonnet 5 Claude-Session: https://claude.ai/code/session_014XePz6Sk4qQsTaP2jVJWJu

Switch to Crafty-style killer ordering; fix mvNullmoveRefutations type-mixing bug and add a quiet-refutation killer backfill.

2026-08-29T07:30:53Z

Killer tiers now try both of this ply's own killers before either ply-2-back one, matching Crafty's ordering. Two earlier attempts at this same swap were reverted for regressing; this pass lands on top of NumLeftoverMovesToSelect (more SelectBestWithHistory budget to reach these lower-tier slots) and a real bug fix below, and beats interleaved order head-to-head on solves, node count, and first-move beta cutoff across the three curated suites. The bug: mvNullmoveRefutations's empty-killer-slot backfill could only ever contain a capturing move (TryNullmovePruning only wrote it inside the capture-refutation branch), but IS_SAME_MOVE's mask includes the pCaptured bits, so that backfilled value could never match a real quiet candidate -- the backfill was silently dead code. Fixed by recording genuinely quiet null-move refutations into a new, separate mvNullmoveQuietRefutations array (kept separate so it can't clobber the capture history mvNullmoveRefutations still needs for the Botvinnik-Markoff same-piece-two-squares extension check) and backfilling the regular killer table from that instead. The check-evasion killer table intentionally does *not* get this backfill: a null-move refutation can never legitimately be an escaping-check move (null moves can't deliver check), so backfilling there risks IS_SAME_MOVE cross-context false positives instead of the old guaranteed-inert no-op. Measured at sd10 across ecm_ringers/ecm_confident_quick/ecm_hard_quick against head_reference (commit d11e973): 115/191 solves (vs. 116 baseline), 924.36M total nodes (vs. 933.23M), first-move beta cutoff within 0.1-0.9 points of baseline on all three suites -- and clearly better than the same fix under interleaved order (113/191 solves, 963.10M nodes), which loses to head_reference on every metric. Co-Authored-By: Claude Sonnet 5 Claude-Session: https://claude.ai/code/session_01EortUUkDVpsfrbqshBJYJg

Document the three-curated-suites testing methodology and the

2026-08-29T05:22:23Z

head_reference protocol. Realized while asking "where is this documented" that it wasn't -- scattered implicitly across lmr_testing/RESULTS.md and head_reference/README.md but never stated as a methodology anywhere durable. Also records the sd-vs-sn guidance (pick based on what the change is expected to affect) and flags the specific gap that cost real time this session: assuming a working tree's disabled-mechanism state matched HEAD's actual committed behavior, when it didn't.

Started doing texel eval tuning.

2026-08-25T02:31:36Z