It took me a while to decide how I should go about this post, even if I should really post in the first place. But with the recent "disavow" tool, I kinda feel obligated. The meat of this post:
Penguin is NOT working
There may not even be such thing as Penguin. I know, there are penalties, but I believe Penguin in general is seriously misrepresented, to say the least.
Recently I decided to enter a new niche. I'm not going into details, but it's rather competitive in the natural results. I have the knowledge, thus I am confident I can compete in this niche, as far as quality content. The first thing I did is to gather the main search keywords and analyze the competition, starting with backlinks, of course. It appeared that about 20 websites are currently occupying the top spots (first page) for the more popular keywords, so I ran ahref on all of them.
You would not believe the backlink profiles! 99% pure unadulterated spam. Site-wide links from foreign websites, blog roll links, almost all (at least 90%) of the backlink profile on ALL of them comes from websites not even remotely related to the niche. I mean things we used to see about 10 years ago. I just don't have the words to describe the "spammyness", blatant and wide in the open. If I showed you the backlink profile of just one of the websites - you will probably punch your monitor and go get drunk.
There is no way in the world that, if Penguin is what it was described to be, it would miss such websites. No way!
I have seen it with my own eyes and I strongly advise everyone to really rethink Penguin.
Now that I have seen this, my personal opinion has changed to: Penguin is just a jolt, most likely designed to bring as much "SEOs" out of the woodwork as possible, as usual based on FUD, or simply to scare them a bit for the future. It certainly is not really targeting anything in particular and seems to work randomly. Add to this that fact that Penguin has not reappeared since it was used for the first time.
I don't think google had any plan about "Penguin", so I have no idea if there is any recovery technique besides just riding it out and hope that one of the thousands yearly changes would trigger something that would improve ones position.