Overtuning, Undertuning and the point of balance.
What us so hard about point of balance? If 3 is too little and 5 too much 4 is just right.
If nerfing an ability by 1 damage won't hurt a champion. Will 2? 3? 4? 5?
If damage being 200 on something is too much, and 50 too little. The right amount is somewhere between them.
I often see people "If you nerf/buff this ability numbers this champion will be dead/OP!" Uhm... by how much. Because if a buff/nerf of 1 wouldn't effect them and a buff/nerf drastically more would break them(either direction) do something between those. And just refine from there.
, that shit will never be balanced with pure number changes.