RankBrain is reportedly the third most important signal Google’s search algorithms use when determining what content to show users in search results. Out of over 200 signals, this is one of the most powerful. And we’ve never heard of it until now.

RankBrain was revealed in a Bloomberg Business interview with Greg Corrado, a senior research scientist at Google. It was introduced into Google’s search algorithm on a wide scale earlier this year, and according to the Corrado, it quickly became the third most important signal out of “hundreds”.

Do you feel like Google’s search results have become significantly better this year? Have you noticed much difference? Share your thoughts in the comments.

So what it is exactly? It’s apparently the first Google ranking signal that actually learns.

For more of a quick “at-a-glance” look at what we know about RankBrain, go here.

Corrado told Bloomberg, “The other signals, they’re all based on discoveries and insights that people in information retrieval have had, but there’s no learning.”

According to the article, a “very large fraction” of Google queries are interpreted by the artificial intelligence system known as RankBrain. It also helps Google deal with “the 15 percent of queries a day it gets which its systems have never seen before,” such as “ambiguous queries, like ‘What’s the title of the consumer at the highest level of a food chain?'” the report explains.

“RankBrain uses artificial intelligence to embed vast amounts of written language into mathematical entities — called vectors — that the computer can understand,” it says. “If RankBrain sees a word or phrase it isn’t familiar with, the machine can make a guess as to what words or phrases might have a similar meaning and filter the result accordingly, making it more effective at handling never-before-seen search queries.”

According to the report, RankBrain has performed better than Corrado and company have expected, and has had a ten percent better success rate than humans at Google asked to guess which results Google would rank number one for various queries. Corrado even indicated that based on experiments Google has run, turning RankBrain off is as damaging to users as turning off half of Wikipedia pages.

RankBrain is only one of many ways Google is increasingly turning to machine learning to improve its products. Google CEO Sundar Pichai discussed the company’s efforts several times throughout Alphabet’s Q3 earnings conference call last week.

In prepared remarks (via a transcript of the call from SeekingAlpha), he told listeners, “Our investments in machine learning and artificial intelligence are a priority for us. Machine learning has long powered things like voice search, translation, and much more. And our machine learning is hard at work in mobile services like Now on Tap, which quickly assist you by providing additional useful information for whatever you’re doing, right in the moment, anywhere on your phone. If you’re an Android user that runs Marshmallow, try it out by long pressing the home button, when you’re in the Map, it’s very cool.”

“Another example is the Google photos app, which leverages powerful machine learning technology to help people discover, organize and share their photos,” he added. ” It’s a great product that people love. In fact, in just a few months since we launched it at Google I/O, photos is now used by over a 100 million users who have collectively uploaded more than 50 billion photos and videos.”

During the Q&A portion of the call, Pichai said, “On mobile search – to me – increasingly we see – we already announced that or 50% of our searchers are on mobile. Mobile gives us very unique opportunities in terms of better understanding users and over time as we use things like machine learning, I think we can make great strides. So my long-term view on this is, it is ask compelling or in fact even better than the desktop, but it will take us time to get there, and we’re going to be focused to be get that.”

In response to a later question, he said, “Machine learning is core transformative way by which we are rethinking everything we are doing. We’ve been investing in this area for a while. We believe we are state-of-the-art here. And the progress particularly in the last two years has been pretty dramatic. And so we are – we are thoughtfully applying it across all our products, be it search, be it ads, be it YouTube and Play et cetera. And we are in early days, but you will see us in a systematic manner, think about how we can apply machine learning to all these areas.”

Clearly machine learning is going to permeate more and more of the overall Google experience as time goes on, and with RankBrain having become such an important factor to search in such a short amount of time, we’d have to expect Google’s search experience to continue to improve rapidly.

RankBrain has reportedly been deployed for a “few months”.

So as a webmaster/site owner, is there anyway you can take advantage of this third most important ranking signal? Unfortunately, there’s probably not a lot you can do to directly influence how RankBrain views your content. That said, the signal could very well help Google better point people to your content as it better understands what users are looking for, particularly when it comes to long tail searches, which still account for a substantial number of queries Google sees on a regular basis.

As for which signals are more important to Google than RankBrain, Google won’t come out and say, but experts in the field like Danny Sullivan think they’re most likely links (the signal that put Google on the map in the first place) and words (as in the words users enter in searches and the words on website’s page).

Do you expect RankBrain to have an effect on SEO strategy? Share your thoughts in the comments.