Gary Illyes from Google explained how Google does ranking in the second part of the Search off the record podcast released yesterday.
He said, Google first cut a no. of pages ranked for a specific query into a small list, then google will apply ranking signals to it or “magic signals” to that cut down list. It happens to the level where the true Google Ranking Magic happens.
At the beginning, to create the small list, Google checks the topic & relevancy regarding query & content of page. Then they use a method to create reverse order list, then it cuts what not to list & then it come up with the 1000 list.
Here only list is created but they are not done with the ranking with the list. He added, in the cut down list the magic begins, the magic signals we put over the results to make better for user’s query. The one best example is Rankbrain, as a magic signals, but he also added a Https boost to another.
If we talk in short, then Google first cuts the searches in a small list according to user’s query & then ranking algorithm & magic algorithm simultaneously works on it.
Then Gary put a light into how it ranks those pages from the list.
Now ranking is number-based. Basically for each result, we will assign a number and we calculate that number using the signals that we collected during indexing plus the other signals. And then essentially, what you see in the results is a reverse order based on those numbers that we assigned.” He added “the magic signals or magic algorithms that we use like RankBrain, what they do is multiply those numbers that we assign to each result by a number. Like for example, if they want to promote a result because it was determined that there would be a better result for lemon coconut cookie, then let’s say that it would multiply the result score by 2. Basically doubling its score, which means that it would jump up in the result set. If we wanted to remove a result from the set for whatever reason, we could multiply its score with 0. Because then, that will turn the score to 0 and then like a score with 0, why would you present that.
Gary then elaborates, it is unlikely that a page would have same score. He added -where there is a HTTPS boost, a magic signal, this is just a tie breakers or small boost. The tie breakers would not rearrange the results unless there is a tie, otherwise it would not rearrange the results.
Kindly check more in the podcast.