Arxiv paper - The Leaderboard Illusion

In this episode, we discuss The Leaderboard Illusion by Shivalika Singh, Yiyang Nan, Alex Wang, Daniel D'Souza, Sayash Kapoor, Ahmet Üstün, Sanmi Koyejo, Yuntian Deng, Shayne Longpre, Noah Smith, Beyza Ermis, Marzieh Fadaee, Sara Hooker. The paper reveals that Chatbot Arena's leaderboard rankings are biased due to undisclosed private testing, allowing some providers to selectively disclose only their best-performing AI variants. It highlights significant data access inequalities favoring proprietary models, leading to overfitting on Arena-specific metrics rather than general model quality. The authors propose actionable reforms to improve transparency and fairness in AI benchmarking within the Arena.