YouTube's search algorithms are increasingly smarter and borrow a lot of things from Google search: advanced operators, spelling corrections, related searches, query expansions. YouTube detects duplicate videos and shows the most popular copy in search results, followed by a link to the other videos. There's also an enhancement for videos that are split in two or more parts: YouTube displays a list of links to all of the episodes.
YouTube Rewind: What you watched in 2013
8 minutes ago