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

Baseline: uPositional data-calibrated fix, enprise/trapped hints, EBF/beta-cutoff/counter-move stats, script.c FPE fix.

2026-08-27T14:42:25Z

No LMR, no counter-move-driven move ordering (both explored separately, kept out for now -- counter-move measured worse, ~655->647 solved on ecm879 @ sn=4M with a leaner tree beforehand). Futility pruning restored. Verified: 647/879 solved, EBF 4.609 @ sn=4M; 684/879 solved, EBF 3.995 @ 20s/move, 1cpu, 256m hash (typhoon_baseline.log). The counter-move table is still written and its stats still tracked (dynamic.c) for diagnostic purposes, but generate.c no longer reads it for move ordering, so it has no effect on search behavior in this commit. lmr_testing/ holds the in-flight graded-LMR + counter-move code (not applied here) with notes on what was already tried and measured, so a future session can resume without re-deriving it.

typhoon.git/src/lmr_testing, branch master

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

Baseline: uPositional data-calibrated fix, enprise/trapped hints, EBF/beta-cutoff/counter-move stats, script.c FPE fix.