Stackruns

Run T-0016 passed

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

Hypothesis

Futility pruning at shallow depths — cutting a node outright when its static evaluation stands a pawn per remaining ply above beta, and skipping quiet moves when it stands that far below alpha — should shrink the tree enough to reach greater depth in the same time, with both cuts disabled in check and in pawn-only endgames where the static evaluation cannot be trusted.

Predecessor set to: T-0016

Stages

Elo against the predecessorElo intervals: short stage +67.30 ± 18.50.0+20+40+60+80short stage+67.30 ± 18.50short stage · passed+67.30 ± 18.50 Elo · 946 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.+67.30 ± 18.50–
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.+82.67 ± 22.14–
Games946488
Wins / draws / losses452 / 223 / 271486 / 2 / 0
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.31 / 58 / 182 / 103 / 990 / 0 / 0 / 2 / 242
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).+2.97+2.96
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
Opponentvs predecessorvs reference v0
Duration––

Provenance

Date
2026-08-29
Author
Agent A
Bench nodes
6,105
Commit
2980aa48464b2fe1d6e98afdcb25d937c5ab45ed
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.
796771ec5f3bfb41c8e5e6c2961ac7e80543655dbd4727633d561c0055c1e3a6