What was already known
OpenAI’s earlier result gave an infinite-plane win within 21 Maker moves and a 17×17 board corollary. Morris’s smaller-board search used moves from that strategy to close three remaining positions.
What changed and why it matters
The smaller board meets Harary’s stated 15×15 benchmark and comes with an explicit strategy certificate. It adds a finite-board theorem rather than another headline for the earlier plane result.
The AI contribution
Morris says Claude Opus heavily drove the work. The pinned notes identify the search, certificate and exposition as machine-produced under his direction, while acknowledging the specific help from OpenAI’s earlier strategy.
Limitations
This concerns the weak maker-breaker game. It does not determine the minimum board size or optimal move count. The separate 17×17, 20-move strategy is credited to Nándor Sieben. AIProofWatch has not run the large certificate checker, compiled Lean, or independently audited equivalence between the informal and formal games.
Verification evidence
Evidence labels show what supports the claim. Importance rates its impact if correct.
Author claim
Pinned author-directed statement of the finite-board win and comparison with earlier work.
Accessible artifact / proof
The project supplies the strategy certificate, a separate checker and reproducibility instructions; these were not executed here.
Formal checking
Maintainer-reported Lean kernel checking of the exact finite-board theorem, not independently rerun by AIProofWatch.
Checker: Trevor Morris project; Lean 4 kernel (reported)
Scope: Snaky.snaky_wins_15x15 under the project’s finite weak-game definitions; no claim of minimum board size or minimum moves.
Basis: Reported by the linked checker
Checking a formal statement does not establish that it matches the original problem.
Correction and publication history
Daily 12 October primary-statement review: a distinct 15×15 board result absent from the full current catalog, with explicit human/AI attribution and reported-checking limits.
Read this published revision