This morning in a Google Hangout on Google+, John Mueller said he is decided to skip a bunch of questions on the topic of being more transparent on what are the specific ranking factors in Google. Questions about why isn't Google more transparent on exactly what you need to do to rank better. What technical changes do you need to make to rank better.
He explained for there may be ticks that get you "a point higher" in the search results but they do not last. They do not last because it doesn't change how relevant your pages are for users and thus the algorithm will adjust and your site will go back to where it was. If Google finds pages are ranking that are not as relevant to users, the algorithms will change to become more relevant.
John added "essentially, for the long run, it is a lot of work for nothing, so that is why I am skipping these questions."
He starts on this topic at around 30:45 into the video and goes on for almost ten minutes.
Here is the video embed:
