Run T-0221 rejected

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

Hypothesis

In non-PV Principal variation: the line of best moves the search currently expects. nodes under specific conditions regarding depth, halfmove clock, beta bounds, and move types, the null-move gate comparisons and reduction are switched to use an adjusted evaluation upper bound instead of the static evaluation. With verification and probe kept as in the baseline, this change is expected to make the engine play stronger.

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

Stages

Elo against the predecessorElo intervals: short stage −2.31 ± 3.17.−6−4−20short stage−2.31 ± 3.17short stage · rejected−2.31 ± 3.17 Elo · 9,322 games
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
Verdictrejected
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.−2.31 ± 3.17
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.−5.14 ± 7.05
Games9,322
Wins / draws / losses2,126 / 5,008 / 2,188
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.7 / 947 / 2812 / 891 / 4
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.−2.95
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 / β0.05 / 0.05
Modelnormalized
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
BookA
Opponentvs predecessor
Duration1 h 10 min

Provenance

Date
2026-10-27
Started
2026-10-27 02:40:23 UTC
Duration
1 h 10 min
Author
Agent D
Epoch
12
Gatekeeper
passed
Bench nodes
603