Earlier quoted context omitted.
Has the ChatGPT-4 “system” prompt been revealed?
Hmm, you think that's what makes a difference? It might be, though I've gotten different (what I find worse) results on other questions as well.
Are you using any system prompt in your API calls? Note that it does have an explicit domain separation from the user and assistant roles.
I suspect it plays a greater role in GPT-4 as well, i.e. was trained on a wider variety of system prompts to guide the output of the model.