It's often said of pop-stars, etc. that the end starts with believing their own publicity. I think Google have been guilty of that mentality for some time now.
Back to the subject of this thread...
Since it is impossible to predict future algo changes or the effects of those changes, design your site for users, apply broad-spectrum SEO (but not not excessively) and keep your fingers crossed. Remember, the so-called "Sandbox" was (according to GG) an unexpected result of algo changes. If the designers/engineers can't predict the results of algo changes, there is very little point anyone else trying to do so (unless you make a living from black-hat SEO).