{"slug": "six-ai-models-played-chess-through-their-clis-none-of-them-delivered-checkmate", "title": "Six AI models played chess through their CLIs. None of them delivered checkmate.", "summary": "A developer behind SpaceApp, a self-hosted workspace for running AI coding CLIs side by side, ran a six-model chess tournament on 18 October in which each model played through its own CLI. No game ended in checkmate; the standings were decided by forfeits, with Opus 5.5 (xhigh) and Gemini 4 Argon (High) tied at 3.5 points and 1535 Elo, while GPT-6-Astra, Fable 5.1, Gemini 3.8 Flash and GPT-6.1-Sol each forfeited two or three games. The developer said the run's real signal was reliability under deadlines — no timeouts, provider errors or illegal moves — which he called the property that matters most when agents run unattended for hours.", "body_md": "I build SpaceApp, a self-hosted workspace for running AI coding CLIs side by side. On 18 October I let six models play chess against each other there, each through its own CLI. Nobody won by checkmate. The way they lost is the interesting part.\n\n| # | Model | Points | W / D / L | Elo | Avg per move | Forfeits | \n|---|---|---|---|---|---|---|\n| 1 | Opus 5.5 (xhigh) | 3.5 | 3 / 1 / 0 | 1535 | 13 s | 0 | \n| 2 | Gemini 4 Argon (High) | 3.5 | 3 / 1 / 0 | 1535 | 23 s | 0 | \n| 3 | GPT-6-Astra (xhigh) | 2 | 2 / 0 / 2 | 1500 | 37 s | 2 | \n| 4 | Fable 5.1 (xhigh) | 1 | 1 / 0 / 3 | 1478 | 26 s | 3 | \n| 5 | Gemini 3.8 Flash (High) | 1 | 1 / 0 / 3 | 1477 | 40 s | 3 | \n| 6 | GPT-6.1-Sol (xhigh) | 1 | 1 / 0 / 3 | 1475 | 34 s | 3 | \n\nTwelve games are a small sample, and a tournament decided by forfeits says very little about chess strength. What it does show is how reliably a model answers through its CLI when every answer has a deadline: no timeouts, no provider errors, no illegal moves, game after game. That is the property I care about most when agents run unattended for hours, and it is not the same ranking you get from a single-prompt leaderboard.\n\nSpaceApp runs on Linux, macOS and Windows 11 with Node.js 20.11 or newer:\n\n```\nnpx --yes run-spaceapp@latest install\n```\n\nIt is source-available under the Business Source License 1.1. Code, docs and known limitations: [https://github.com/oll4com/spaceapp](https://github.com/oll4com/spaceapp)\n\nIf you have run something similar, I would like to know which models held up for you, and which rules you would change for a fairer second run.", "url": "https://wpnews.pro/news/six-ai-models-played-chess-through-their-clis-none-of-them-delivered-checkmate", "canonical_source": "https://dev.to/space_app_fc7f6872808dc84/six-ai-models-played-chess-through-their-clis-none-of-them-delivered-checkmate-4fhp", "published_at": "2026-10-19 17:05:14+00:00", "updated_at": "2026-10-19 17:14:57.452067+00:00", "lang": "en", "topics": ["ai-agents", "large-language-models", "ai-tools", "developer-tools"], "entities": ["SpaceApp", "Opus 5.5", "Gemini 4 Argon", "GPT-6-Astra", "Fable 5.1", "Gemini 3.8 Flash", "GPT-6.1-Sol", "GitHub"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/six-ai-models-played-chess-through-their-clis-none-of-them-delivered-checkmate", "markdown": "https://wpnews.pro/news/six-ai-models-played-chess-through-their-clis-none-of-them-delivered-checkmate.md", "text": "https://wpnews.pro/news/six-ai-models-played-chess-through-their-clis-none-of-them-delivered-checkmate.txt", "jsonld": "https://wpnews.pro/news/six-ai-models-played-chess-through-their-clis-none-of-them-delivered-checkmate.jsonld"}}