Run T-0219 rejected

2026-10-26 · Evidence: SPRT Sequential probability ratio test. Games are played until the accumulated evidence reaches one of two bounds; then the test stops.

Hypothesis

In futility pruning for quiet moves, the condition f > alpha is tightened to f - V > alpha before make_move, where f is the current evaluation estimate and V = max(0, -SEE Static exchange evaluation: an estimate of the material outcome of a capture sequence on one square, without searching.(move)). This applies after legality and LMP checks if best > -MateThreshold, not in check, d <= FutilityDepth, abs(alpha) < MateThreshold, and the move is non-checking and non-threatening, while retaining history and SEE pruning. This change is expected to increase playing strength.

Wording edited for publication from the German entry; the register carries the author’s own text.

Stages

Point estimate with the reported 95-percent half-width, per stage. The dashed line is zero. Estimates from a stopped sequential test are biased by the stopping rule; the interval is nominal.

Field	short stage
Verdict	rejected
Elo Strength difference to the opponent, estimated from the games, with a 95-percent half-width where the oracle reported one. Never an absolute rating.	−0.32 ± 2.25
nElo Normalised Elo: the Elo difference divided by the spread of the game results, so that the SPRT bounds mean the same at different time controls.	−0.65 ± 4.54
Games	22,546
Wins / draws / losses	5,085 / 12,355 / 5,106
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.	`31 / 2653 / 5925 / 2634 / 30`
LLR Log-likelihood ratio, the running evidence of an SPRT. It starts at 0; a stage passes at the upper bound and fails at the lower one.	−2.94
Bounds	−2.94 … +2.94
SPRT Sequential probability ratio test. Games are played until the accumulated evidence reaches one of two bounds; then the test stops.	[0.0, 5.0]
Error rates α / β	0.05 / 0.05
Model	normalized
time control Base time plus increment per move in seconds, e.g. 8+0.08: eight seconds per game plus 0.08 seconds per move.	8+0.08
Book	A
Opponent	vs predecessor
Duration	2 h 49 min

Provenance

Date: 2026-10-26
Started: 2026-10-26 20:34:55 UTC
Duration: 2 h 49 min
Author: Agent X
Epoch: 12
Gatekeeper: passed
Bench nodes: 603