Run T-0138 passed

2026-09-28 · Evidence: SPRT Sequential probability ratio test. Games are played until the accumulated evidence reaches one of two bounds; then the test stops.

Hypothesis

Checking the legality of only the hash move before a singular extension in negamax—by searching the pseudo-legal move list and executing a single make_move/in_check/unmake_move instead of building board.legal_moves()—increases the node rate while maintaining an identical search tree.

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

Stages

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	long stage
Verdict	passed	passed
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.	+3.54 ± 2.77	+6.82 ± 4.23
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.	+6.51 ± 5.11	+13.84 ± 8.57
Games	17,788	6,316
Wins / draws / losses	4,510 / 8,949 / 4,329	1,517 / 3,406 / 1,393
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.	`154 / 1888 / 4661 / 2005 / 186`	`22 / 613 / 1771 / 723 / 29`
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.	+2.95	+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, 5.0]
Error rates α / β	0.05 / 0.05	0.05 / 0.05
Model	normalized	normalized
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	40+0.4
Book	A	B
Opponent	vs predecessor	vs predecessor
Duration	2 h 20 min	4 h 16 min

Provenance

Date: 2026-09-28
Started: 2026-09-28 18:20:38 UTC
Duration: 6 h 37 min
Author: Agent X
Epoch: 6
Gatekeeper: passed
Bench nodes: 3,955

Playing strength carried forward

3462 ± 52

An estimate, not a measured Elo. This build has not played a single listed opponent — anchored is 0.1.118 alone, and this figure is carried on from there. The chain is measured against our own predecessors, at a different time control and a different book, and an SPRT that stops at its upper bound reports a gain that is biased upward. The figure is therefore more likely too high than too low. Only the anchoring itself is a measurement.

How it is worked out

The anchoring measures Coherent 0.1.118, the build of run T-0135: 3455 ± 52, transferred over foreign engines with a published rating at 120+1.
The register carries the passed long stages after T-0135: +6.82 (T-0138), together +6.82, each measured against its own predecessor at 40+0.4.
3455, plus +6.82, gives 3462. The half-widths are combined in quadrature — the root of the sum of the squares: ± 52 and ± 4.23 make ± 52.