Researcher Finds Fable 5.1 Superior for Long Math Problems

Dimitris Papailiopoulos reported using Fable 5.1 since morning for a multi-day hard math problem spanning Codex and CC threads. He called it more creative than Sol and far ahead of opus 5. Yuchen Jin posted that the model talks like a normal human rather than Claudish, remains weaker than GPT-5.6 Sol at web search, yet outperforms GPT models at frontend work, while keeping Kimi K3 as daily driver. sdmat described the model as better at grasping big-picture codebase structure and coordination. Victor Taelin noted an extremely productive day and said the model felt launch-ready.