🇺🇸 Derek Liu

The paper and the marking

Contestants sit two papers on consecutive mornings, three problems each, four and a half hours per paper. Each problem is worth seven points and is marked by coordinators who work through the argument as written, awarding partial credit for genuine progress and withholding it for gaps.

That marking system is what makes a clean scoresheet unusual. Most strong contestants collect a mixture of sevens, small partial scores and zeros. Liu's 2023 line has no partial score in it.

The American record in context

The United States sends six contestants, like every other country. In 2019, at the olympiad in Bath, two Americans wrote perfect papers, Colin Shanmo Tang and Daniel Zhu. In 2023 the American maximum was Liu's alone, and at the 2026 olympiad in Shanghai two more American contestants, Liam Reddy and Alexander Wang, joined the list.

Those are the only years covered by this file, so the sequence is not a complete history. What it does show is that a perfect American paper is a roughly annual possibility rather than a routine event, in a team selected from the strongest secondary-school mathematicians in the country.

Who shared the top of the table

The other perfect scorers in Chiba were Haojia Shi and Chunji Wang of China, Junhwi Bae of South Korea and David-Andrei Anghel of Romania. All five are listed at rank 1; the olympiad does not separate contestants who reach the maximum.

Five perfect papers was a middling year by the standards of this record: 2022 in Oslo produced ten, 2026 in Shanghai produced seven, and 2024 in Bath produced exactly one. The count tracks the difficulty of the problems as much as the strength of the field.

What the official record holds

Everything on this page comes from the competition's own results database: the host city, the field size, the country, the six problem scores, the total, the rank and the medal. It is maintained by the olympiad and is the reference used by national teams and by the press.

It publishes no ages, schools, cities or photographs. There is therefore no birth year on this page, no school name and no home town, because inventing any of them would be the one error this file refuses to make.

What is not known here

No later olympiad appearance for Liu is recorded in the results consulted for this page, and no newspaper or university report naming him was collected for this file.

Readers should also be careful with the name itself. Derek Liu is not unusual, and biography pages assembled from search results frequently merge several people who share it. This page claims only what the 2023 database entry for the United States team states.

The competition itself supplies the reason the record is so thin. The IMO is an individual examination for students still at school, and the organisation publishes scores rather than biographies, on the reasonable ground that most of its contestants are minors. The result is a public achievement attached to an almost entirely private person, and filling that space with invention is how most of the misinformation about olympiad competitors begins.