Engine arena run: completed

Paired contrast slot 0 minus slot 1: +0.051 wins per game over 64 seeds (95% interval -0.044 to +0.146).

Planned: 256
Attempted: 256
Completed: 256
Incomplete: 0
Unplayed: 0

Full retained record and provenance

Run bbc86639-f6ef-4d40-9d26-604fa8a4573a

Status: completed. Experiment: 4c43f642-044e-4b09-850a-e2cf38fb3b30. Tier: engine arena (paired seeds, deterministic tapes).

Planned: 256. Attempted: 256. Completed: 256. Incomplete: 0. Unplayed: 0.

Slot / seat	Wins	Completed	Win rate	95% Wilson interval	Mean points	Mean decision
0 / `v2:{"depth":2,"endgame":{"block_leader":true}}`	108	256	42.2%	36.3%–48.3%	7.70	149.2 ms
1 / `v2:{"depth":2}`	95	256	37.1%	31.4%–43.2%	7.33	146.6 ms
2 / `eta`	31	256	12.1%	8.7%–16.7%	6.73	0.2 ms
3 / `fast`	22	256	8.6%	5.7%–12.7%	6.55	0.2 ms

Paired contrast slot 0 minus slot 1: +0.051 wins per game over 64 seeds (95% interval -0.044 to +0.146).

Manifest SHA-256: 55db18a2fa59b1a63db4b45c68dd4875c2f785ef36569c138872c557285637c7. Inventory SHA-256: 4f83cfee5bc7d7f794c78f154a5d63f249dcc5458014b8b2df60fbbf95a3fed1.

Games were played offline by the engine arena with explicit seeds; every seed was played once per lineup rotation. Seats received only their own redacted observation and participant events. This tier supports development and diagnosis; it is not a protocol-arena confirmation.