The outlier score on a video is how far it beat what that channel normally gets.
A score of 6x means the video did six times the views that channel usually does. It is a comparison against the channel's own median, not against the platform.
Why it is built that way
View counts on their own tell you how big an account is. They do not tell you whether a video worked.
A creator with two million followers getting 300,000 views had a quiet day. A creator with 8,000 followers getting 300,000 views did something you should look at closely. The raw number is identical and the lesson is the opposite, which is why sorting by views buries exactly the videos worth studying.
Scoring against the channel's own baseline fixes that. A small account can out-score a huge one, and usually does, because a breakout is easier to see against a small median.
What it is useful for
Sort a Watchlist or a creator's page by outlier score and you get the videos that broke that account's pattern, newest first. Those are the ones where something changed: a different hook, a different format, a topic that landed.
That is the question worth asking about a competitor. Not what do they post, but what did they post that beat their own average, and what was different about it.
Where you will see it
On video cards in Discover, in a Watchlist and on a creator's page. As a sort option on both Watchlist and creator pages. On a format, as an average across every video using that format, with a rank against the rest of the library.
Your weekly brief uses it too. A post from someone you track has to clear twice their median before it counts as an outlier finding at all.
What it does not tell you
Nothing about whether the video was good, and nothing about whether it will work for you. It says this video beat its own channel's normal by this much, and that is worth a look.