From 7857096f39e16619a42ee85b4aa593abd846b74a Mon Sep 17 00:00:00 2001 From: Scott Gasch Date: Wed, 26 Aug 2026 11:50:25 -0700 Subject: Replace ctx->uPositional with a data-calibrated Eval() return value. uPositional was a per-thread EWMA of abs(material - true score) used to size lazy-eval and futility margins. It was history-derived (reflecting whatever recent, unrelated positions looked like) rather than derived from the position actually being margined, and its update/consumption was tangled with EVAL_HASH (now disabled). Eval() now takes an optional SCORE *piPositional out-param and fills it in on every return path: exact (abs(material-delta)) on a full eval, or an estimate from a new EstimatePositionalScore() on a lazy exit. EstimatePositionalScore()'s two terms (king-safety-defect-bucketed, and a flat residual for mobility/passers/everything else) are calibrated from ~1.6M measured full-eval samples (p90 of the actual swing), not guessed -- an initial guessed version measurably regressed ECM solve rate (630 vs a 650 baseline at sn=4M); the recalibrated version is back at parity (649/879). search.c's qsearch futility now reads the value Eval() just computed instead of the stale/shared ctx field. Also removes QSearchInDangerNoStandPat and SideCanStandPat, dead since the danger-hash check that fed them was already commented out (e08387a) -- they depended on the same enprise/ trapped-piece data this conversation is about to move off of g_PositionHash entirely. Co-Authored-By: Claude Sonnet 5 --- src/searchsup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/searchsup.c') diff --git a/src/searchsup.c b/src/searchsup.c index 9a2cc50..0cf52bf 100644 --- a/src/searchsup.c +++ b/src/searchsup.c @@ -804,7 +804,7 @@ Return value: Trace(" \t"); } - iEval = Eval(&temp, -INFINITY, +INFINITY); + iEval = Eval(&temp, -INFINITY, +INFINITY, NULL); Trace("%5s (%+2d) | ", ScoreToString(iEval), temp.sPosition.iMaterialBalance[temp.sPosition.uToMove] / 100); Trace("%5s (%2u) | ", -- cgit v1.3