Google Update: Why You Are Seeing a Drop In Impressions & Increase In Average Position

Each month I carry out an audit of site and search performance for clients who I provide performance insights support for.

For each one, in September, I noticed a strange pattern in search performance.

Each site saw a drop in search impressions, but an improvement in average position.   This didn’t make sense.   If the site was seeing an improvement in rankings, why are impressions dropping.   The following shows this across my and 3 other client sites:

Further to that, you will see for the most part, clicks have not been affected massively either way, so it was all seemingly a bit odd and didn’t stack up.

Over recent months (years even), I’ve seen a number of shifts in search results due to the inclusion of things like shopping results, AI overviews, video result, image results etc – the Google SERPs are an ever changing landscape which always seem to chip away at your organic traffic.

So the first thing I do when I see something like this is search “Google alogrithm Update + month”.

And this is what I found out:

Google Algorithm Update: September 2025

Around 10-15 September 2025, Google quietly removed support for the &num=100 URL parameter.

That parameter was commonly used by SEO tools and browser extensions to force Google to show 100 search results on one page instead of the default 10.

For years, those automated tools have been responsible for a huge amount of impressions being logged in Search Console — especially for keywords where your site ranked beyond the first page. Every time one of these bots or tools loaded a results page with your listing on it, it counted as an impression.

When Google removed &num=100, those automated “impressions” instantly disappeared. The data now reflects more realistic, human-based visibility, mainly within the first few pages of results.

Why this caused impressions to drop

Because Search Console reports an impression whenever your URL appears in search results, removing those deeper-page bot loads meant that all impressions from positions 20-100 effectively vanished overnight.

If your site ranked for lots of longer-tail keywords that appeared low down (page 3, 4, 9, etc.), those impressions are no longer being counted. That’s why you see a sharp drop in total impressions, particularly on desktop (most SEO tools use desktop search results).

Why average position improved

Your average position is the mean of all ranking positions where your site received an impression.
When all those low-ranking impressions disappeared, only the higher-ranking ones remained — for example, positions 3, 8, 12 instead of 3, 8, 12, 75, 93, 97.

Mathematically, that makes your average position look better, even though your real rankings haven’t changed.

How to confirm this is the cause

You can check a few things to be sure:

• Compare desktop vs mobile in Search Console — the desktop version will show the drop, mobile will look mostly normal.
• Look at Google Analytics (GA4) — if your organic traffic and conversions stayed steady, it’s just reporting noise.
• Check the timing — if the change started around 10-15 September, this aligns exactly with the &num=100 removal.

In short

This wasn’t a ranking drop or an algorithm change — it was a reporting correction.
Google effectively stopped counting automated, non-human impressions that were never real searchers to begin with.

Your visibility to real users hasn’t changed; the data just looks cleaner now.

About The Author

I’m Dave Ashworth — a freelance SEO and website optimisation consultant with a background in development and a focus on fixing what’s broken, improving what’s working, and helping businesses grow through clear, practical SEO.

I combine hands-on technical know-how with years of experience in analytics, content strategy and platform optimisation. Whether it’s an audit, a migration, or ongoing performance support, my work’s about making websites stronger, faster, and easier to understand — for users and for search engines.

When I’m not writing guides or sharing insights, I’m working directly with clients to solve problems, track results, and keep their sites moving in the right direction.