The Keyword Difficulty is a metric that, on 3 levels (easy, medium, hard), estimates the effort it would take for a specific website to rank in the top 10 positions for a keyword.
How does this work?
First off, the Difficulty is calculated/updated whenever a keyword:
is added to the Rank Tracker,
enters or exits the top 10,
enters or exits the top 100, or
has a significant rank change.
We use 2 keyword database sources to extract the necessary data for the estimation:
our own keyword databases – for the UK, the US & RO markets.
3rd party keyword databases, for the rest of the world.
There are 2 algorithms for estimating this keyword difficulty based on ranking:
For keywords in Top 100
The core metric used for calculating the difficulty metric is the Topical Authority:
= estimated monthly organic traffic a page would get, based on keyword rankings and search volumes.
It is calculated for each of the 100 ranking landing pages in the keyword’s SERP and then the following key variables are computed:
Delta Page Authority
The difference in Page Authority, also called Delta Page Authority, is the difference between your landing page’s Authority and the Authority of the landing pages in the Top 10.
[Delta Page Authority] = [Your page Authority] / [Avg. Top 10 Authority]
The output is simplified into 3 values in terms of difficulty:
HIGH: [Delta Page Authority] < 0.1
MEDIUM: [Delta Page Authority] >= 0.1 and <= 0.5
LOW: [Delta Page Authority] > 0.5
Distance until Top 10
We analyze the presence of the keyword in the ranking page’s title, to understand how focused the content of the page is. Usually, when a page ranks in the top 100 and the content is not focused on the keyword, the rankings could be significantly improved with just some content updates. And that would make it easier for the user to improve the page ranking, towards the top 10 (lower Difficulty).
But when the content is already focused on the keyword, it would need Authority improvement, which is harder to get (higher Difficulty).
This distance takes into account how many pages with higher authority and with the same or lower-focused content on the keyword rank ahead of yours.
We calculate the Authority for all ranking pages, from your current rank and up to rank #11
For estimating the Content Focus, we do the following:
The keyword is split into individual words (>3 characters).
We then search for these in the Title of your page and of all the pages that have a higher Authority than yours, and we output [No/Partial/Full Match] as a parameter.
Finally, depending on the keyword match within your page title, the algorithm counts the higher authority pages in front of you, as follows:
No match → only counts the pages that have “No match” in the title
Partial match → counts the pages with “No match” / “Partial match” in the title
Full match → counts all pages
The final output is simplified into 3 values (of difficulty), depending on the number of more authoritative pages ahead of your page:
LOW: [# Higher Authority Pages] <= 10
MEDIUM: [# Higher Authority Pages] < 50 and > 11
HIGH: [# Higher Authority Pages] >= 50
Free slots in Top 10
This is simply the number of positions in the top 10 where there are NO big global players – which are unlikely to drop out of the top 10 (like Youtube, Facebook, Wikipedia, Amazon, Google, LinkedIn).
[FREE SLOTS] = the number of positions in the top 10 where
there are no "big sites" that would keep their ranks within the top 10.
The output is also simplified into 3 values in terms of difficulty.
HIGH: [Free Slots] <= 3
MEDIUM: [Free Slots] >3 and <=7
LOW: [Free Slots] > 7
The final calculation
Combinations of the difficulty levels on each of the 3 metrics then give us the EASY/MEDIUM/HARD Keyword Difficulty.
For keywords outside Top 100
On the US/UK/RO markets
To estimate the keyword difficulty for a website not yet ranking in the top 100, we look at how many pages target the keyword in their Title, partially or fully.
We split the keyword into separate words (longer than 3 characters) and search for it in the Title of the page, in all its forms (singular, plural, verb, etc). We’ll further refer to these as [Other pages with partial match].
We also analyze your best-ranking* page’s keyword-title match, with the same process. We’ll further refer to it as [Keyword in your page’s title]. It can take 3 values: No/Partial/Full Match.
Depending on whether the page has the [Keyword in title] and the number of [Other pages with full/partial match], we process the final difficulty as EASY/MEDIUM/HARD.
Keywords where your website ranks outside the Top 100:
[X] authoritative landing pages with a full match of the keyword in the title.
[Other Pages with Partial Match] authoritative landing pages with a partial match of the keyword in the title.
Keywords where your website ranks within the Top 100:
10-[Free Slots] big website(s) in top 10 (e.g: wikipedia),
[# Higher Authority Pages] more authoritative landing pages in front of you,
If [Delta Page Authority] = LOW:
The top 10 LPs' authority and yours are comparable.
If [Delta Page Authority] = MEDIUM:
The top 10 landing pages' authority is slightly higher than yours.
If [Delta Page Authority] = HIGH:
The top 10 landing pages' authority is significantly higher than yours.
(Quickly) finding out low-hanging fruit in any list of tracked keywords.
Build a good keyword strategy by avoiding keywords that are too difficult to pursue (for the time being).
Showing clients why you chose to focus on some keywords and not on others, to then create transparency and credibility with them.
And showing clients how these choices make your predictions more realistic.
It's not a generic Keyword Difficulty, but the Difficulty to rank in top 10. Further within the top, it could be too sophisticated for the SEO needs. If your site is ranking within the top, you're already optimizing. So a top 10 metric is good enough, while also keeping the result relevant.
Because the Difficulty is relative to the ranking landing page, the same keyword tracked in multiple campaigns could have different Difficulty values.
And when the ranking improves, the difficulty gets easier and easier, until the page reaches the Top 10.