There have been many studies that have shown a correlation between backlinks and ranking (being in the top X results) on Google for a particular keyword. However, nobody has really studied whether there is a correlation between being #1 and backlinks for pages that already are in the top 10 results.
In this article, we see whether that correlation exists.
Table of Contents
- Correlation between backlinks and ranking
- Interpreting the results: is there a correlation?
- Key points
Correlation between backlinks and ranking
Ever since Google became the dominant search engine in the early 2000s, the number of backlinks to a site has been of utmost importance in how that site ranks in SERP results.
In fact, the first paper that proposed the Google search engine was about using backlinks to determine importance of content on the Internet.
However, more recently, Google appears to be relying less and less on backlinks. Or at least, it seems that way. Google has been testing using deep learning and natural language processing to understand content for ranking.
There is still empirical evidence that backlinks are important and that they do help determine whether a site ranks. But how well a site ranks — especially among the top 10 results — may no longer be based on backlinks.
This article details the results of a study that we performed this month to answer this question.
For this study, have a dataset of 500 random search queries. For each search query, we have taken the first SERP page and used Ahrefs to determine the number of backlinks for all of the results on that page.
We count the number of queries for which the #1 result on Google has the most backlinks to determine if there is a correlation between backlinks and the #1 result. If this number is statistically significant, there is a clear correlation.
For each SERP we will measure two different backlinks quantities: the total number of backlinks, and the number of unique linked domains. The number of unique linked domains is a count of the backlinks to a site when only one backlink is counted per linking domain.
We found that of the 500 search requests we performed, 157 of the SERPs had the result with the most backlinks in the #1 spot. This is a rate of 31% approximately. 281 of the SERPs had the page with the most domains linked to it as the #1 result. That is about 56%.
Although the number of linked domains is greater than 50%, we must calculate the z-score to determine if the value is statistically significant:
z = (.56 – .5)/sqrt(.52/500) = 2.68, which is outside the 95% confidence interval
Therefore we do have a statistically significant result: there is a small correlation between domain links and ranking #1 on Google. However, the very small proportion means that you’re only slightly more likely to rank #1 if you have the most backlinks on the first page.
The backlinks result is a bit more surprising. There’s no benefit to having the most backlinks, if you’re already ranking on the first page. What’s important is the number of linking domains — and even that is not critical.
Finally, we calculate the proportion of #1 SERP results that either have the most backlinks or the most domains linked. That number is 280, or again around 56%. While it’s statistically significant, it’s only slightly over 50%.
Interpreting the results: is there a correlation?
There is a statistically significant correlation between number of domains linking to a page and whether they’re #1 on the first page of SERP results. But practically, the correlation is so small that it’s essentially useless.
What this means is that there is very little benefit to continuing to build backlinks for a page once you’ve made it to the 1st page of SERP results. I interpret this to mean that once you have made it to the first page of the Google results for a search term, you’re best off spending your time and effort on improving the content and on-page SEO as opposed to collecting backlinks.
There are some caveats, of course. Presumably, over time, competing sites will be collecting more and more backlinks, so to remain on the first page, you may have to as well. Also, Google is constantly changing the weightings for its algorithm, so backlinks may matter more among first page results in the future.
Backlinks are important for getting to the first page on Google, but they’re only a tiny part of what separates a #1 result from a #10 result.
We did find a statistically significant correlation between being #1 and number of domains linked to a page, but it’s a very slight correlation and not worth planning content around.
The upshot is: if you’re already on the first page for a particular keyword, focus less on backlinks and more on content quality and on page SEO. Whether you buy or build a website, understanding where to focus will save you time and money.