Rather than splitting the PageRank equally between all links on a page, some links are valued more than others. There’s speculation from patents that Google switched from a random surfer model (where a fatiguer may go to any link) to a reasonable surfer model (where some links are more likely https://bookmarkworm.com/story19298897/le-5-deuxi%C3%A8me-truc-pour-placement-manuel-de-liens