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

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.

1 files changed, 58 insertions, 0 deletions

diff --git a/src/lmr_testing/generate_counter_move_block.c b/src/lmr_testing/generate_counter_move_block.c
new file mode 100644
index 0000000..f58efda
--- /dev/null
+++ b/src/lmr_testing/generate_counter_move_block.c
@@ -0,0 +1,58 @@
+// generate.c changes to restore counter-move scoring. Three pieces, in
+// the same function (the one with PRECOMP_KILLERS sKillers[...] and the
+// "Pre-populate killer/bonuses" comment -- search for that to find it).
+
+// LOCATION 1: local var decls at top of the function -- add mvLast and
+// pi, bump sKillers to 6:
+//
+//   PLY_INFO *pi = &ctx->sPlyInfo[ctx->uPly];      // ADD
+//   ULONG uPly = ctx->uPly;
+//   POSITION *pos = &ctx->sPosition;
+//   ULONG u;
+//   MOVE mv;
+//   MOVE mvLast = (pi-1)->mv;                        // ADD
+//   SCORE s;
+//   MOVE_STACK_MOVE_VALUE_FLAGS mvf;
+//   ULONG uHashMoveLoc = (ULONG)-1;
+//   ULONG uColor = pos->uToMove;
+//   PRECOMP_KILLERS sKillers[6];                     // was [4]
+//   COOR cEnprise = FindEnprisePiece(ctx, uColor);
+
+// LOCATION 2: right after the killer sKillers[0..3] population block
+// (after the SORT_THESE_FIRST |= lines for sKillers[0..3]), insert:
+
+    //
+    // Pre-populate counter-move bonuses -- keyed by whatever move the
+    // opponent just played to reach this node, not by ply.  A/B test:
+    // applied as a small *additive* nudge (like history counters),
+    // not a hard priority-tier flag -- the ~56% measured hit rate
+    // isn't confident enough to justify unconditionally outranking
+    // ordinary PSQT-scored quiet moves.  Bonus scales with the ply
+    // depth the entry was recorded at (deeper = more confident),
+    // capped at the same 400/200 ceiling the flat version used.
+    //
+    sKillers[4].mv.uMove = sKillers[5].mv.uMove = 0;
+    if (mvLast.uMove != 0)
+    {
+        u = MOVE_TO_INDEX(mvLast);
+        sKillers[4].mv = ctx->mvCounter[u][0];
+        sKillers[4].uBonus = 400;
+        sKillers[5].mv = ctx->mvCounter[u][1];
+        sKillers[5].uBonus = 200;
+    }
+
+// LOCATION 3: in the quiet-move scoring branch (the `else` branch that
+// computes `s = g_iPSQT[...]` and applies killer bonuses via `s |= ...`),
+// right after the GOOD_MOVE/cEnprise line and before `ASSERT(s >= 0);`,
+// add (note: additive `+=`, not `|=` -- this was the measured-best
+// config vs. a hard flag):
+
+                s += (IS_SAME_MOVE(sKillers[4].mv, mv) * sKillers[4].uBonus);
+                s += (IS_SAME_MOVE(sKillers[5].mv, mv) * sKillers[5].uBonus);
+
+// This same three-part change applies in BOTH scoring functions in
+// generate.c that have this sKillers array (there are two -- one for
+// the normal move-scoring path, one for escaping-check; check whether
+// the second one had the counter-move block too before assuming it's
+// identical -- verify via `grep -n PRECOMP_KILLERS generate.c` and
+// diff both call sites against this file's saved state if unsure).