User blog comment:Demise101/So I was thinking..../@comment-3360527-20110725044733

HP could work but I don't think it would be as effective. It is more visible (HP bar) and is suseptable to simple harassment. AD stacking is doable, mostly for ranged dps since melee ones have to get into (shocker) melee range to use it fully. AP is the most viable of all of the stats to stack IMO for the reasons you already stated. I have an ARAM AP rune page specifically for this reason with magic pen reds, AP quints and blues and i think mp5 yellows so I start with 24 AP before items for strong early harass.