Run T-0207 rejected

2026-10-24 · Evidence: SPRT Sequential probability ratio test. Games are played until the accumulated evidence reaches one of two bounds; then the test stops.

Hypothesis

Omitting both preference-learning branches and the final history update (including bonuses, penalties, capture history, killers, and countermoves) at the end of the search when the best score equals the draw score before the final draw clamp, while retaining transposition-table cutoff killers, evaluation, research, and correction learning, returns, and table stores, increases the engine's 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.	−1.94 ± 3.18
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.	−3.92 ± 6.45
Games	11,130
Wins / draws / losses	2,472 / 6,124 / 2,534
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.	`15 / 1326 / 2944 / 1266 / 14`
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.	−2.96
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	1 h 24 min

Provenance

Date: 2026-10-24
Started: 2026-10-24 16:49:40 UTC
Duration: 1 h 24 min
Author: Agent D
Epoch: 11
Gatekeeper: passed
Bench nodes: 603