It's a bit unfair. ChatGPT has a version that is so expensive that it appears nobody on that leaderboard used it [1]. It is called ChatGPT 5 Pro and its priced at $120/1M tokens. Claude Opus 4.5 has a price of $25/1M tokens [2]. Gemini 3 Pro is $18/1M tokens (assuming more than 200k tokens) and Sonnet 4.5 is $22.5/1M tokens (same assumption). I would expect that ChatGPT 5 Pro would be better than any of these other models, but I have no way of testing.

The next most expensive OpenAI model is ChatGPT 5.1, which costs only $10/1M tokens, so significantly cheaper than all its competitors. It seems to me that's fair for this model to come on the 3rd or 4th place, given that.

[1] https://openai.com/api/pricing/

[2] https://www.claude.com/pricing#api

[3] https://ai.google.dev/gemini-api/docs/pricing