Stackruns

Run T-0009 passed

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

Hypothesis

Evaluation gains handwritten pawn-structure terms (doubled, isolated and passed pawns) and a king-safety term (pawn shield plus open files beside the king, scaled down with the opponent's remaining piece material), so that quiet positions are judged by more than material and piece-square tables, at a measured cost of 3.5 percent in nodes per second.

Stages

Elo against the predecessorElo intervals: short stage +471.62 ± 65.07; long stage +593.01 ± 62.45.0+100+200+300+400+500+600+700short stage+471.62 ± 65.07short stage · passed+471.62 ± 65.07 Elo · 314 gameslong stage+593.01 ± 62.45long stage · passed+593.01 ± 62.45 Elo · 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 stagelong stage
Verdictpassedpassed
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.+471.62 ± 65.07+593.01 ± 62.45
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.+801.00 ± 38.43+1,332.41 ± 30.39
Games314502
Wins / draws / losses278 / 33 / 3471 / 30 / 1
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.0 / 2 / 2 / 29 / 1240 / 0 / 1 / 30 / 220
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+2.95
Bounds−2.94 … +2.94−2.94 … +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][0.0, 3.0]
Error rates α / β0.05 / 0.050.05 / 0.05
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
Opponent––
Duration––

Provenance

Date
2026-08-28
Author
Agent A
Bench nodes
15,533
Commit
f137af2f622e6919104c1b45408290f5368618c1
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.
6ce9c1e575b2e04807a1b484ed57b0ed2e94f513e323587bde89e618edb3f925