Pangram’s 99% AI Score for an Award-Winning Novel

El País reported on October 23, 2026, that Pangram 4.1 classified 99% of the roughly 26,000-word novel Donde el agua trabaja as AI-generated. The score is a text classification; Editorial Almadía said author David Silva Rojas denied using AI and called for a detailed review.

What Pangram classified

The reported 99% result came from a scan of the whole novel with Pangram 4.1. El País also reported separate scores of 97% AI for Silva Rojas’s answers in a magazine interview and 80% for a 924-word first-person account about the book. Those figures concern different texts, not additional scans of the novel.

Donde el agua trabaja won the first Premio Internacional de Novela Breve Almadía Ventosa-Arrufat in July 2026 and was published in September, according to El País. The contest’s published rules, reproduced by Escritores.org, prohibited entries written partly or entirely with AI.

What Almadía said after the result

El País reported that Editorial Almadía said Silva denied using AI. The publisher called for a detailed review without anticipating its conclusions and suspended the book’s planned presentation events.

How detector benchmarks relate to one novel

A University of Chicago working paper published on August 26, 2025, evaluated Pangram and other detectors using 1,992 human-written passages across six genres, including novels, alongside AI-generated passages from four language models. The paper reported near-zero Pangram false-positive and false-negative rates on medium-to-long passages in its tested corpus. It also noted that changing a detector’s threshold changes the balance between those two types of error. The benchmark describes performance on its test corpus; it is not an examination of Silva Rojas’s manuscript.

Pangram Labs’ July 29, 2026, technical report gave Pangram 4 an AUROC of 0.9916, a false-positive rate of 0.0041%, and a false-negative rate of 0.3396%. These are company-reported benchmark metrics. They describe Pangram’s reported test performance, while the 99% figure describes its classification of this particular novel.