In this a16z AI podcast, LMArena founders Anastasios N. Angelopoulos, Wei-Lin Chiang, and Ion Stoica discuss the current state and future directions of AI evaluation with a16z general partner Anjney Midha. The conversation highlights the shift from static benchmarks to real-time, real-world evaluations, emphasizing the importance of mass-scale testing and diverse user feedback for AI reliability. They explore the concept of private arenas for specific industries, the role of subjective measurements, and the challenges of disentangling style from substance in AI responses. The discussion also covers the evolution of LMArena, its open-source approach, and the technical challenges of achieving granular, personalized AI evaluations, including the development of Prompt-to-Leaderboard and Red Team Arena. The founders underscore the importance of neutrality, innovation, and community trust as they transition from a research project to a company, aiming to make AI systems more reliable and aligned with human preferences.