https://arstechnica.com/information-technology/2024/05/before-launching-gpt-4o-broke-records-on-chatbot-leaderboard-under-a-secret-name/

On Monday, OpenAI employee William Fedus confirmed on X that a mysterious chat-topping AI chatbot known as "gpt-chatbot" that had been undergoing testing on LMSYS's Chatbot Arena and frustrating experts was, in fact, OpenAI's newly announced GPT-4o AI model. He also revealed that GPT-4o had topped the Chatbot Arena leaderboard, achieving the highest documented score ever.