Interpreting the Google Trends Index for Sports Events

What the number means

Google's help pages describe two steps. First, each data point is divided by the total searches of the place and time range it represents. Second, the results are scaled from 0 to 100 based on a topic's proportion of all searches. So 100 is the highest share in your chosen view, and 50 is half that share. Google's News Initiative training says it directly: numbers on the graph do not represent absolute search volume.

Two consequences matter for sports. A final can score 100 in one country and 40 in another while having far more searches in the second, because each view is scaled on its own. And adding or removing a comparison term rescales every line in the chart.

Sampling, noise and zeros

• Sampling. Trends uses a sample of Google searches, which Google says is sufficient to represent the whole. Repeat the same query on another day and small values can shift.
• Noise. Google says Trends data will sometimes reflect statistical noise rather than actual search interest, especially for queries with low interest.
• Zeros. Terms with low volume appear as 0. For a niche fixture, a flat zero line means "too small to show", not "no interest".
• Filtering. Repeated searches from one person over a short period are removed, and queries with apostrophes and some special characters are filtered out.

Time zones and event days

Google Trends uses UTC for ranges of 30 days or more, and your own time zone for ranges of 7 days or less. A Monday night NFL game in the eastern US happens on Tuesday in UTC. An Ashes session in England happens overnight in Melbourne. Before you label a peak "match day", check which clock the chart uses. Search Console uses yet another clock: its Performance report labels daily data in Pacific Time, except the 24-hour view.

A reporting checklist

1. Record the query, place, time range, category and date you pulled the data.
2. State that values are relative (0 to 100) and not search volumes.
3. Note the time zone the chart uses for that range.
4. Compare like with like: the same place and period, with the same comparison terms.
5. Keep the export file. A chart without its settings cannot be checked later.

Questions

Is a Google Trends score of 100 the same as high search volume?

No. 100 is the peak share of searches for that term in the place and period you chose. Google says the numbers do not represent absolute search volume.

Why does my Trends chart change when I add a term?

All terms in a comparison are scaled together, so adding or removing one rescales the others. Save each chart with its exact settings.

What time zone does Google Trends use?

UTC for ranges of 30 days or more, and your browser or device time zone for ranges of 7 days or less, according to Google's help page.

Sources

1. Google Trends Help, FAQ about Google Trends data, no date shown.
2. Google Trends Help, FAQ about Google Trends data (data sources and time zones), no date shown.
3. Google News Initiative, Google Trends: Understanding the data, no date shown.
4. Search Console Help, Performance report: troubleshooting data discrepancies, no date shown.