LoL Item Optimizer is a program that computes the best build for any champion using math. The finely tuned variable presets guarantee that the builds will always be viable, both on paper and in actual games! This is the ultimate theorycrafting tool, available for all players, and is extremely easy to use.
Item OP tries every possible item combination and displays the most cost efficient build of the following 3 attributes:
Damage is calculated by comparing the damage output difference of each of the weighted combat scenarios. Example:
Durability is calculated by comparing the expected surviving time difference. Varies on enemy team damage composition, overhealing / shield duration of your abilities, etc (lots of algebra involved)
Utility is an arbitrary variable that accounts for movement speed, slow, and other special effects that can't be mathematically evaluated. The user uses his own judgment to determine how much a utility is worth.
Example: If you are willing to trade off 10% of your damage for 10% movement speed then that is the trade-off value