Hot chips come in many shapes and sizes. Some people prefer thick 'n' chunky steak fries. Others are more partial to the classic French fry. More still prescribe to crinkle cut (these people are weird). Whatever your chip preference, this algorithm will ensure they turn out perfectly, every time. (Micky Mouse/Amphibious Landing Craft shape not included.)
Blake Lingle is the cofounder and co-owner of the Boise Fry Company, so he knows a thing or two about frying up potatoes. The flow chart below -- from Lingle's book Fries!: An Illustrated Guide to the World's Favourite Food -- breaks down the science required for perfect chippies.
It covers the potato choosing process, how thick to cut them and how to prepare them so they're the crispiest, most-flavorful fries you've ever had. Unfortunately, the cooking temperatures are all in Fahrenheit but this is nothing a little Googling or mental arithmetic can't remedy. To enlarge, open the pic below in a separate tab.