Stackruns

Run T-0220 rejected

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

Hypothesis

For non-promotion quiet killer and counter moves that futility pruning would discard but history and SEE Static exchange evaluation: an estimate of the material outcome of a capture sequence on one square, without searching. allow, the veto is changed across all node types. The move and the legal countermove from history are executed, followed by a grandchild quiescence search with a null window at alpha. Only a score above alpha releases the move for regular search, otherwise it is discarded as before; 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 −0.94 ± 2.62.−4−20+2short stage−0.94 ± 2.62short stage · rejected−0.94 ± 2.62 Elo · 16,272 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.−0.94 ± 2.62
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.−1.91 ± 5.34
Games16,272
Wins / draws / losses3,685 / 8,858 / 3,729
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.24 / 1899 / 4328 / 1867 / 18
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.−2.97
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
Duration2 h 02 min

Provenance

Date
2026-10-27
Started
2026-10-27 00:01:18 UTC
Duration
2 h 02 min
Author
Agent X
Epoch
12
Gatekeeper
passed
Bench nodes
603