Run T-0042 failed

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

Hypothesis

Restricting quiescence stalemate checks to low-material positions without an unblocked pawn should correct drawn endgame scores without paying for legal move generation on common stand-pat exits.

Stages

Elo against the predecessorElo intervals: short stage −9.79 ± 7.47.−15−10−50short stage−9.79 ± 7.47short stage · failed−9.79 ± 7.47 Elo · 4,542 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
Verdictfailed
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.−9.79 ± 7.47
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.−13.26 ± 10.10
Games4,542
Wins / draws / losses1,479 / 1,456 / 1,607
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.204 / 513 / 942 / 431 / 181
LLR Log-likelihood ratio, the running evidence of an SPRT. It starts at 0; a stage passes at the upper bound (about +2.94) and fails at the lower one (about −2.94).−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 / 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
Duration32 min

Provenance

Date
2026-08-30
Started
2026-08-30 09:18:22 UTC
Duration
32 min
Author
Agent B
Bench nodes
3,786
Commit
f8704964ab5411de64186a6a24d53b3b11e8e6d1
SHA-256 A cryptographic hash. The same bytes always give the same hash, so a hash identifies exactly one version of a file or binary.
54b0e2d7832cf5df4dd32bb0e61b4ef7776167f936a971f58c5fa607f1c5b021