Stackruns

Run T-0223 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 not in check and without exclusion under a non-mate window, countermove maintenance is modified: the quiet countermove read before the move loop is cleared from its unmodified slot if it was legally searched to at least positive nominal child depth, returned a non-mate score at or below alpha, and a tactical move subsequently achieves beta. 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 +4.66 ± 3.31; long stage +0.56 ± 2.10.−20+2+4+6+8short stage+4.66 ± 3.31short stage · passed+4.66 ± 3.31 Elo · 10,284 gameslong stage+0.56 ± 2.10long stage · rejected+0.56 ± 2.10 Elo · 24,286 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 stagelong stage
Verdictpassedrejected
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.+4.66 ± 3.31+0.56 ± 2.10
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.+9.46 ± 6.71+1.16 ± 4.37
Games10,28424,286
Wins / draws / losses2,421 / 5,580 / 2,2835,334 / 13,657 / 5,295
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.11 / 1131 / 2728 / 1253 / 197 / 2756 / 6578 / 2795 / 7
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.+2.96−1.35
Bounds−2.94 … +2.94−1.34 … +2.71
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][0.0, 5.0]
Error rates α / β0.05 / 0.050.05 / 0.25
Modelnormalizednormalized
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+0.0840+0.4
BookAB
Opponentvs predecessorvs predecessor
Duration1 h 17 min15 h 36 min

Provenance

Date
2026-10-27
Started
2026-10-27 06:07:13 UTC
Duration
16 h 53 min
Author
Agent X
Epoch
12
Gatekeeper
passed
Bench nodes
603