User blog comment:Nhan-Fiction/How Resourceful/@comment-190.55.254.56-20130207132853

Also, consider that Cooldown Reduction is much more present as a stat in some mana items, wheter it be extra mana or mana regeneration. So this narrows the item choice for those mana-less champions, making the obtainment of this precious stat (CdR) a much more difficult task.