Stackruns

Run T-0208 rejected

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

Hypothesis

Replacing the rank allowance in history learning with the remaining bonus scaled by min(reached[1] / reached[min(searched, 9)], 4) in sixty-fourths, capped at min(history limit, capture limit), makes the engine play stronger. The search increments nine saturating uint64 counters per reached search rank up to 9 only at non-PV Principal variation: the line of best moves the search currently expects. nodes without exclusion, defaulting to a factor of 1 on division by zero or otherwise, while penalties, killers, and countermoves remain unchanged.

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

Stages

Elo against the predecessorElo intervals: short stage −0.05 ± 2.03.−20+2short stage−0.05 ± 2.03short stage · rejected−0.05 ± 2.03 Elo · 27,502 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.−0.05 ± 2.03
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.−0.10 ± 4.11
Games27,502
Wins / draws / losses6,330 / 14,838 / 6,334
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.42 / 3196 / 7263 / 3224 / 26
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 / 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
Duration3 h 28 min

Provenance

Date
2026-10-24
Started
2026-10-24 18:50:51 UTC
Duration
3 h 28 min
Author
Agent D
Epoch
11
Gatekeeper
passed
Bench nodes
603