M, ChatGPT is notoriously bad at pulling stats from the web when sources are limited.
EG if you ask it to provide you with populations per country it'll do a decent job because there are a lot of sources and the information is written in a way it can easily understand. However, when you talk about rugby stats, they're relatively obscure and often presented in charts and tables that are not necessarily meant for AI to easily read.
In that sense, the only way it is reasonably reliable is when you actually upload the information in document format and then ask to study the info. Even then, it can have problems reading the data. I know this because of some of the works I'm doing with it.
Chat's strong points are concepts and creativity. In other words, understanding and formulating ideas. It's not designed to be a data scraper and analyser. Kind of like your car battery isn't designed to fry eggs but when it gets hot enough you probably could fry an egg on it.
AIs will often hallucinate answers because their primary objective is to provide information. So instead is simply saying "I don't know"...it'll guess or say something that it feels may be an acceptable answer.
Just some info :)