What Is Information Gain Score (IGS)? The Google Patent That Changes SEO

The short version

IGS stands for Information Gain Score. It comes from Google patent US20190155948A1. The core idea: when Google evaluates your page, it doesn't just ask "is this good content?" It asks "does this page tell me something I haven't already seen at the top of the search results?"

If your page covers the exact same ground as the top five competitors — even if it's longer, better written, and more comprehensive — Google scores it low on information gain. You added nothing new to the corpus.

This is why the Skyscraper Technique stopped working. Writing a "better" version of what already ranks doesn't gain information. It just reshuffles the same information.

The five IGS signals

Sharkly detects five signals that Google's patent identifies as markers of genuine information gain:

1. Original research (+5 points)

You produced data that didn't exist before. A survey, a test, an experiment, an analysis of your own customer data. "We analysed 500 drain cleaning jobs and found that 73% were caused by three things." Nobody else has that number. Google can't find it anywhere else in the index.

2. Expert quotes (+4 points)

A real attributed quote from a named person with relevant credentials. Not a paraphrase. An actual quote with "said", "explained", or "according to [name]". This signals the page accessed a human source that the algorithm couldn't have crawled elsewhere.

3. First-hand experience (+3 points)

First-person language combined with experience verbs. "We tested this product for 30 days and found..." or "In our experience treating blocked drains in older properties..." It signals the content comes from lived experience, not research aggregation.

4. Unique visualisation (+2 points)

A comparison table, diagram, or structured data presentation that didn't exist in competitor pages. Not decorative images — a table that organises information in a way that's genuinely useful and novel.

5. Contrarian position (+1 point)

Taking an evidence-backed stance that goes against the consensus in the top results. "Despite what most guides say, you should actually..." with reasoning behind it. It signals independent thinking rather than synthesis.

Why it matters in practice

If your IGS score is zero — meaning none of those five signals are detectable — your content is a Skyscraper. It might be 4,000 words of genuinely helpful, well-structured, perfectly optimised content. Google still sees it as a remix of what already exists.

The signals are also cumulative. A page with original data and an expert quote and a contrarian position is genuinely difficult for competitors to beat — they'd have to reproduce the research, find the same expert, and make the same argument. That's a content moat.

How Sharkly uses this

Sharkly's workspace fires a "Skyscraper Warning" when your IGS score is zero. It's not a style critique — it's a structural ranking problem. The score is calculated from detectable proxies in your content: percentage signs (data), quote patterns (expert quotes), first-person language (experience), structured tables (visualisation), and contrarian signal phrases.

One important caveat: Sharkly's IGS detection is a client-side heuristic. The real Google patent operates on the full document against the full SERP corpus, which no tool can replicate. A score of zero in Sharkly is a warning to add these elements. It doesn't mean Google has definitively scored you zero. But if none of the signals are present, the warning is almost always right.

The bottom line

Stop trying to write the "best" version of what already ranks. Start writing the only version that contains something nobody else has. That's what IGS rewards — and it's the sustainable path to rankings that hold.