All you really have to do is time it. Slightly different time for different-sized eggs and how many you have in the pot. Most people just simply boil them too long, thinking once it’s hard-boiled, there’s no damage that can be done. Also, hard-cooked is the more descriptive term, not hard-boiled.
You’re right about that. My way is not the only way, but most people over boil...
Isn’t this great, getting excited about an egg?