The AI Models Index tracks premium model releases from 15 labs since 2023,...

https://riversinterestingthoughtss.wpsuo.com/who-held-1-on-lmarena-the-longest-since-august-2024

The AI Models Index tracks premium model releases from 15 labs since 2023, verifying launch dates and using blind votes to ensure accuracy. Updated every two weeks, it shows a steady pace—like the 4.5 days between GPT-5.1 and GPT-5