Run T-0090 passed

2026-09-19 · Evidence: SPRT Sequential probability ratio test. Games are played until the accumulated evidence reaches one of two bounds; then the test stops.

Hypothesis

Trivial board getters such as side_to_move, key, halfmove_clock, en_passant_square, castling_rights, and fullmove_number are inlined in the header to allow embedding without LTO. Additionally, has_non_pawn_material is optimized to iterate over the set bits of occupied() instead of using a 64-square loop. Together, these tree-neutral changes yield an expected speedup of approximately +4.04% nps with identical search behavior.

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.	+8.45 ± 6.63	+16.78 ± 10.59
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.	+12.90 ± 10.12	+26.40 ± 16.62
Games	4,526	1,678
Wins / draws / losses	1,391 / 1,854 / 1,281	531 / 697 / 450
pentanomial Games are played in pairs with swapped colours; the five counts are the pairs scoring 0, ½, 1, 1½ and 2 points.	`113 / 459 / 1015 / 557 / 119`	`27 / 168 / 394 / 197 / 53`
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	+2.97
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, 10.0]	[0.0, 10.0]
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	34 min	1 h 04 min

Provenance

Date: 2026-09-19
Started: 2026-09-18 23:44:20 UTC
Duration: 1 h 38 min
Author: Agent X
Epoch: 5
Gatekeeper: passed
Bench nodes: 2,608

Playing strength carried forward

2951 ± 62

An estimate, not a measured Elo. This build has not played a single listed opponent — anchored is 0.1.93 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 0.1.93, the build of run T-0087: 2891 ± 59, transferred over foreign engines with a published rating at 120+1.
The register carries the passed long stages after T-0087: +25.23 (T-0088) +17.97 (T-0089) +16.78 (T-0090), together +59.98, each measured against its own predecessor at 40+0.4.
2891, plus +59.98, gives 2951. The half-widths are combined in quadrature — the root of the sum of the squares: ± 59 and ± 20.53 make ± 62.