🇺🇸 Vivian Loh

The maximum score

The EGMO 2023 scoreboard records Vivian Loh of the United States on 42 points out of 42 with a gold medal. Six problems, seven marks apiece, and a seven in every column of her row.

Her team-mate Isabella Zhu scored the same. Teams at EGMO consist of four contestants, so half the American team produced flawless papers, a feat matched in 2023 only by China, whose four contestants all reached the maximum.

A tie that cannot be broken

Fourteen perfect scores in one year leaves the competition without an individual winner. Medals at olympiads are awarded by band rather than by rank, so all fourteen carry gold, and so do a number of scores beneath them, but the scoring system has no tie-break to apply above 42.

The other perfect papers in 2023 belonged to all four Chinese contestants — Shuwen Hu, Lai Yuan, Sihan Su and Yiran Qiu — and to Fidan Garayeva of Azerbaijan, Maria Drencheva of Bulgaria, Nogah Friedman of Israel, Polina Henyk of Ukraine, Xiangyue Nan of Australia and two Turkish contestants, Melek Güngör and İrem Gülce Yazgan.

How the marking works

EGMO problems require proofs, and the marks follow the argument rather than the answer. Scripts are assessed through coordination between the examiners and the team leaders, who go through each solution together, so partial credit reflects how far a chain of reasoning genuinely reaches.

That is what makes 42 the hardest number on the scoreboard to obtain. It is not a matter of speed or of arriving at correct conclusions, but of six written arguments that leave nothing for a determined examiner to challenge.

Nothing about the process favours the quick. Contestants work for hours on six propositions whose statements fit in a paragraph each, and the only evidence that counts is the reasoning they commit to paper. A perfect score is the rarest outcome that system produces, and in most years it produces none at all.

The year after

The next olympiad shows how rare the 2023 cluster was. At EGMO 2024 in Tskaltubo, Georgia, the highest score in the world was 41, by Hannah Fox of the United States, with two contestants sharing second place on 38. Nobody reached the maximum.

Between them the two scoreboards make the point that a perfect score is as much a fact about a particular set of six problems as about the person who solved them. In 2023 the paper could be exhausted; twelve months later it could not.

What is documented — and what is not

The firm facts are the official scoreboard's: 42 points out of 42 for Vivian Loh at EGMO 2023 in Portorož, Slovenia, a gold medal, competing for the United States, alongside thirteen other perfect papers.

Nothing else appears in these sources. No age, date of birth, school, state or photograph, no interview and no record of results before or after 2023. Whether she competed at other olympiads is not documented here, and no later report has been found in the material gathered for this page.