HAGonline is a Dutch / Flemish website trying to answer your question regarding Hattrick. HAG stands for Het Antwoord Genootschap, which is Dutch for The Answer Community. And impressive amount of answers they provide.
Chance conversion
The most interesting content I found were the chance conversion statistics. Or what are the odds that your chances get converted to actual goals, based on your attack and his defense ratings. This is just 1 example of interesting information. If you want to know something about Hattrick then you can probably find it on HAG online.
Contribute
As there’s more to know about hattrick from research then from the rules. It’s possible to contribute to Hattrick research on HAG online!
English
Most of the content regards figures. So you might onderstand it no matter which languages you speak. Try using a translation plugin for your browser if you need more clarity on what is said.