GSC `&num=100` retirement September 2025 — Search Engine Land: 87.7% of sites lost impressions, 77.6% lost unique ranking terms; LOCOMOTIVE 319-site single-study caveat

Claim: In September 2025, Google retired the &num=100 URL parameter that had allowed showing 100 results per SERP page. This removed bot-inflated deep-rank impressions (where rank-trackers and crawlers had been triggering impressions for positions 11-100 that no real user saw).

Search Engine Land (Danny Goodwin, September 18, 2025), citing LOCOMOTIVE's Tyler Gargula analysis of 319 properties:

• 87.7% of sites lost impressions in Google Search Console.
• Unique ranking terms (query count) fell for 77.6% of sites.

This is a reporting cleanup (removal of bot impressions), NOT a traffic loss.

Source: Search Engine Land (Danny Goodwin, Sept 18, 2025); LOCOMOTIVE / Tyler Gargula 319-property analysis.

Confidence: Verified (event + reporting); Single-source on the headline percentages.

Caveat: Single-study caveat: the 87.7% / 77.6% figures rest on a single 319-site study, not multiple independent confirmations. The directional finding (impressions and query counts dropped industry-wide on Sept 2025 from a reporting change) is consistent across observer reports, but the precise percentages are LOCOMOTIVE's number, not an established benchmark. Year-over-year impression comparisons spanning Sept 2025 must be annotated.