How do «bad neighbors» negatively affect link quality in Google?

Decided to start a series of posts about Google patents, if you like this kind of thing, I'll keep picking at it Google Patents and share the information with you

Google Patent: US9183499B1

Status: Active

The quality score model to provide a quality score that considers the features of neighboring entities.

Patent US9183499B1, issued to Google in 2015, describes a method for evaluating the quality of objects (e.g., websites) by considering the characteristics of their «neighbors» - related objects such as websites.

The model in this patent analyzes

1. Quality of other sites: If they have high quality scores, it can have a positive impact on your page ranking.
2. Average quality score of neighbors: Using the average quality score of neighboring sites to determine the quality of the site in question.
3. Updating grades: As the quality scores of neighboring sites are updated, the quality scores of related sites are recalculated.

Thus, the presence of links to other sites on a page affects the quality score of your site through the average quality score of those «neighbors». High-quality neighboring sites may increase your score, while low-quality sites may decrease it.

What counts as «neighbors» - a hosted site on a page with your link or on any donor page?

A patent uses the term «object» which can be:

• Web page
• Site (host)
• Or even another entity that has an identifier and characteristics

This means that not only pages but also objects linked through the link graph are taken into account:

1. Neighbors can be on other pages of the same donor site.
2. They are accounted for through the link connectivity graph, including two- and three-link links.

It turns out that if the site on which you bought a link starts selling links to low-quality resources, it can lead to deterioration of the reputation of the donor and reduce the effectiveness of your link in search engines, which is logical, since links from PBN and trust resources (media and fat hosts with high DAU) give a strong boost to sites that are placed on them