[{quoted}](name=Photos of Ghosts,realm=EUW,application-id=3ErqAdtq,discussion-id=zqftOBKt,comment-id=00020000,timestamp=2016-03-25T06:01:27.961+0000)
I understood perfectly and I said exaclty what you said.
I just gave a bit too high of an estimation with my 0.3 if it equals 50% on average. But I'm pretty sure this isn't the case, IIRC even someone like Cho reaches 1.0 AS lategane, which means 0.3 would be equal to 30%
No, your post shows you exactly didn't understand.
Everyone has a base AS of around 0.625. All bonus AS is calculated based on a percentage of that.
For example, Phantom Dancer gives 55% additional AS. That means the item itself gives 0.625*0.55 bonus attack speed to the holder, which is about 0.4 attacks per second.
The attack speed growth per rank is also calculated in the same manner. Kog'maw gains 3% of his base AS as bonus AS per level, so assuming he has a base AS of 0.625, he gets 0.625*0.03 per level of his champion. Cho'gath has an AS of 1.0 attacks per second, but his base AS remains the same throughout his game. Base Attack Time of a champion never changes.
Now, if an item gives 0.3 attacks per second on a champion with 0.625 base attack speed, it amounts to about ~46% additional attack speed if he were to purchase items that gave additional attack speed, such as Stattik Shiv. The amount of attack speed given by (0.3 attacks per second) is in fact, higher than the current 25% additional attack speed when Lifeline activates in almost all cases, unless the champion had higher than 1.2 attacks per second as a Base Attack Time (who unfortunately does not exist).