Edit: To clarify, "improve your benchmark" is not a viable strategy by itself any more than "put your opponent in checkmate" is a viable strategy. As advice it is unhelpful. You generally have to mitigate flaws in the way you rank pages, keep large parts of the algorithm secret, and attack the economic viability of your adversary's strategies. Rather than going for checkmate, you want your opponent to resign so you can do something else instead.
There have been incentives for bad behavior on the web for so long that I don't think we have any hope of coming up with any kind of automated benchmark to tell us which pages have good user experience.