Advanced league stuff: True damage math challenge
I was mentioning earlier that tanking is kindof complicated against true damage. It requires some advanced knowledge but one could call anything "advanced" so i'd like to see just how much it takes to demonstrate this. I have my own way but maybe some math wiz could simplify it for me.
First we pick a champ

then we need to conceptualize what their true damage actually does
Does it rapidly whittle you down? 
does it burst in a narrow aoe pattern 
does it periodically chunk you? 
but then I want to see how it actually impacts the game.. for example, when the receiving end was built optimally (a few years back) vayne would effectively penetrate 25% of their defensive gold value (not that any item is perfectly 100% gold efficient to begin with), I'd like for people to put numbers like that into place but in simple, NON-MISLEADING terms. Misleading as in stupid shit that will cause people to lose a lot of games like saying
makes defense useless.
Don't forget to suggest "mathmatically ideal" damage prevention builds if you can. Remember to simplify it as much as you can. You want to basically make a guideline that says who you are playing or want to be playing or emulate and if they need more of a certain type of item. Factor in how much damage said champ will be dealing as well under the assumption that vayne is not going to be terribly tanky if at all or that lifesteal or spellvamp will be significant on them.