We gave Fable 5 Ultracode and Codex 5.6 Sol Ultra the exact same prompt. One shot. No help. They played 10 games against each other. Final score: Fable 10 -Codex 0
Gave the same prompt to two AI coding agents: Claude (Fable 5, ultracode multi-agent mode) and OpenAI Codex (5.6 sol on ultra). The task: a complete, fully legal chess engine in ONE C++ file. UCI protocol, negamax alpha-beta at 5+ ply, iterative …