Ok so I see a lot of people raging over armor pen and black cleaver. What exactly is wrong with it?? And what is the difference between flat armor pen and %armor pen. And what exactly does stacking mean? So would someone plz explain the whole concept

Stacking is just the act of buying multiple items for a certain stat. So I buy 3 Black Cleavers I'm stacking them. Black Cleaver is getting raged at in my opinion because of it's passive being easy to proc allowing for massive armor shred and the stats are really good for many AD champions just in general making it a good buy for those who can abuse the item's passive proc.

Difference between flat pen and % is that % is based on the amount of armor your opponent has and it's used first when calculated. While flat is just an amount that taken off directly from your opponent's armor and is calculated second between the two.

So if your opponent has 100 armor and you have 10% armor pen + 10 Armor pen flat, you'd first take away 10% of his 100 armor which would be 10 then you'd take away the flat 10 afterwords making the enemy's armor value 80 when damage is calculated. Which means the reduction to your damage is actually reduced by a fair amount and that your hitting harder.

With the changes to % and flat it is also now possible to basically shred away all your opponent's armor but idk if there is any possible item setups for that yet.

Thanks so I could buy 5 black cleavers and the enemies armor would be off by 50%