Excessively Flat Site Hierarchy May Confuse Google
An excessively flat site architecture, such as having a very large sitewide navigation or linking to all pages in a paginated set from page 1, may confuse Google about the site hierarchy, which page to rank, and what to show as Sitelinks.
Headings and Titles on Paginated Pages Helps Google to Identify the Set
Headings and page titles with a number help Google to identify a set of paginated series of pages which belong together, but they can usually figure it out based on links between the pages.
Ensure Google is Able to Crawl All Pages Involved Within Infinite Scroll
When implementing infinite scroll, ensure Google is able to reach all of the pages involved. John recommends the best way to do this is by linking to all the pages individually through a pagination set up, to ensure each page can be crawled.
Be Cautious Implementing Infinite Scroll on Publishing Sites
John recommends being cautious implementing infinite scroll on publishing sites because having multiple pieces of content in the same HTML might be confusing for Google if they are individual pieces of content.
Viewport is Expanded During Rendering & Likely to Trigger Infinite Scroll Once or Twice
When a page is rendered, Google expands the viewport and then contracts it to try to fit the primary content on the page. Expanding the viewport could trigger one or two infinite scrolls on pages with this functionality, but would not cause Googlebot to keep triggering this and infinitely crawling pages.
Cross-link Pages to Help Ensure Google Can Discover Them to Decrease Reliance on Pagination
Focusing on improving internal linking across product and blog post pages is a good strategy for ensuring Google is able to find these pages on your site rather than relying on pagination.
Google No Longer Uses Rel=Next/Prev to Understand Pagination
Google no longer uses rel=next/prev to understand pagination. John stated that there are no changes that SEOs need to make if pagination is working properly in search, as long as internal linking is in place.
Google Doesn’t Treat Paginated Pages Differently From Any Other Pages
John explained that Google treats paginated pages in the same way as any other page on a website. While Google does try to understand how pages fit into the context of a website as a whole, they do not apply an attribute to pages to indicate it is a paginated page.
Rel=next/prev May Still Be Useful Even Though No Longer Used by Google
Although rel=next/prev is no longer used by Google, John doesn’t recommend removing it from a site as it is still used by some browsers for prefetching and by other search engines.