Dynamic move-ordering/LMR session: honest FH tracking, decoupled admission/magnitude, bugfixes, tooling

2026-10-04T15:17:52Z

Lands the 2026-09-28..10-03 move-ordering investigation (full history in lmr_testing/*.md). Summary of what ships: LMR/move-ordering redesign (searchsup.c, dynamic.c, data.c, chess.h): - GetLMRReduction's admission decision (do we reduce at all) is now decoupled from magnitude (how much): LMR_STATIC_ADMIT_THOUSANDTHS=500 gates admission via the 4D joint fail-high table (data.c) plus a countermove-match veto; magnitude is a flat Crafty/Ethereal-shaped log(depth)*log(moves) table (g_iLMRQuietReduction), which measured as good or better than the old per-tier joint-table payout while being structurally immune to the per-bucket miscalibration that sank the tiered approach. g_FailHighs honesty fix (real 0/0 init, not a fake prior) underlies the dynamic-danger signal. - Retired NumLeftoverMovesToSelect's depth-indexed selection budget -- evidence showed the leftover pool has real findable signal a bailout was discarding. - ShouldLatePrune (overt late-move pruning) implemented but disabled at its call site -- measured net-negative at the tested threshold; kept for reference and as a base for a future hang-bucket-9-targeted retry. - PRUNE_VERIFY, PRUNE_LIVE, DISABLE_LMR: opt-in diagnostic build flags (GNUmakefile), off in the standard profile. Bug fixes found and fixed while exercising this work: - JOINT_EXTRA_TIER_COUNT 4->6 (chess.h): fixed an out-of-bounds counter write reachable at remaining depth >= 14 (unreachable at sd10, routine in real search/self-play). - Node-type instrumentation (search.c, root.c, searchsup.c): fixed four compounding defects that produced impossible percentages (e.g. 106.2% of PV nodes) -- wrong denominator, qsearch misclassified as main search, untyped early-exit nodes, and fail-low tests using the in-place-raised alpha instead of the initial one. - FH-rate unit unification (search.c, searchsup.c, dynamic.c, chess.h): GetMoveFailHigh* returned per-mille while g_uJointFHThousandths is thousandths-of-a-percent, two different units sharing a "_THOUSANDTHS" suffix. Unified to one scale, renamed to "_PCT_THOUSANDTHS". RateBucket's band edges fixed to match. - QSearch option B (search.c): waives the opponent-stand-pat requirement at NODE_PV only (sound there since the exact score propagates; not sound at null-window nodes). iExtensionAmount unit fix (was 0/2 into a ONE_PLY-scaled field). pi->iEval now published when Eval() runs. - eval_tune/match_play.py local_ebf: was reporting 0.000 in every match since 2026-09-18 (regex only matched the trailing-stats parser, not the live move-scan loop; engines were also spawned with "nopost" so root.c never emitted the lines at all). True per-ply EBF is ~2.0, not the ~3.9 every prior match report implied. - eval_tune/test_vs_head.sh: positional-arg shift ordering bug caused every no-extra-args run to silently rebuild ./typhoon with a non-standard profile and, separately, could feed a flag's value in as the candidate binary path. - PERF_COUNTERS cleanup (eval.c, search.c): moved 3 leaked rdtsc sites to the existing EVAL_TIME guard, deleted two concluded one-off diagnostics (u64HeadStyle*, u64FHJointHist/RateBucket/AttemptsBucket) and their report plumbing, and re-gated a per-move hang-material estimate behind FH_TABLE_COLLECTION instead of running it unconditionally. Infrastructure: - match_play.py time-odds support (--odds/--st-head/--st-candidate), validated against the engine seat rather than color. - Wilson-upper-bound re-bake of the joint table (data.c): cells store a confidence-aware bound instead of a raw point estimate, so a consumer can threshold on the value alone; monotone, so every consumer became strictly more conservative. Verified behavior-neutral for LMR. Known-open items (not resolved here, see lmr_testing/GET_LMR_REDUCTION.md section 10 and 2026-10-03_UNCOMMITTED_TRIAGE.md): the self-play gate on this candidate is underpowered (+5 Elo, 95% CI roughly [-6, +17]); the curated-suite solve-count deltas used earlier in the investigation turned out to be noise-dominated cancellation when diffed per position, not the clean signal they first appeared to be. Co-Authored-By: Claude Sonnet 5

typhoon.git/src/lmr_testing/2026-10-03_UNCOMMITTED_TRIAGE.md, branch master

Dynamic move-ordering/LMR session: honest FH tracking, decoupled admission/magnitude, bugfixes, tooling