Engine arena run: completed

Paired contrast slot 0 minus slot 1: +0.160 wins per game over 64 seeds (95% interval +0.057 to +0.263).

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

Full retained record and provenance

Run 9109daab-18d0-4a2a-94e3-a7fa11c94a7a

Status: completed. Experiment: 6c2d07c6-e7f0-4f91-8e75-43e590f1b1f1. 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,"robber":{"need":true}}`	130	256	50.8%	44.7%–56.8%	8.38	224.8 ms
1 / `v2:{"depth":2}`	89	256	34.8%	29.2%–40.8%	7.39	210.5 ms
2 / `eta`	24	256	9.4%	6.4%–13.6%	6.77	0.2 ms
3 / `fast`	13	256	5.1%	3.0%–8.5%	6.37	0.2 ms

Paired contrast slot 0 minus slot 1: +0.160 wins per game over 64 seeds (95% interval +0.057 to +0.263).

Manifest SHA-256: abc56e2c3e3075f8aa150aa420222aa4c483db4204083bd4e7d167e2069a9f0c. Inventory SHA-256: 643b76c9b2bb1404e75944351bd1aa4c3ea47f8571e82c5e8ea701982b26a96e.

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.