Google’s Matt Cutts just posted a video on YouTube answering the question, “how many search algorithm changes were made in 2009?” In response to that question, Matt said Google likely makes a change per day to the search algorithm. They don’t necessarily release those changes each day, but they will release them in batches. But overall, he hopes to average at least one change per day to the algorithm. He said in 2009, they probably had between 350 to 400 or so changed to the search algorithm.
A few months ago we covered a Wired story on Google’s algorithm where Udi Manber, Google’s head of search said Google has introduced 550 “improvements” to the search algorithm in the past year alone. So I guess Matt was being conservative with his math?
Here is the video: