A good friend of mine got in touch to let me know he'd finally reversed the effects of a Panda update that affected his site greatly in Dec 2012. His approach was to go through every page and improve them by making them more useful and targeted to various informational search queries. His is not a site that sells product.
While that sounds typical what isn't typical is that all of the pages which needed work the most were ranked in the 150 range of serps. After improving them and regaining traffic these are mostly now ranked between 4th and 6th in serps. It would seem there hasn't been a second Panda/Penguin update since his recovery and so top spots are currently off limits to him?
Do you think this yields credence to the possibility that the top few spots are baked in somehow? He'll find out after the next couple of updates if he can regain top spot or not but right now his stats do suggest a ceiling, not that he's complaining... he'll take it so to speak.
Has anyone witnessed something similar after a recovery?