Sudoku FlowSudoku news, October 2026
Edition of October 7, 2026 · News from September 1, 2026 to October 7, 2026.
The World Sudoku Championship comes to Kolkata, India, this month, with a public puzzle day during championship week. Plus the Czech championship, the first results on the road to the 2027 championship in France, and two new research papers that use Sudoku.
A public puzzle day during championship week
October 14, 2026
On 14 October the championship opens its doors with Puzzle Palooza at the Westin hotel in Kolkata, from 2 pm to 7 pm. According to Beebom, Will Shortz will host a general quiz for teams of one to three, and Thomas Snyder a mini games contest for solo players.
Sources: Beebom: Puzzle Palooza in Kolkata, WSPC 2026: official schedule
World Sudoku Championship 2026 in Kolkata
October 12, 2026
The World Sudoku and Puzzle Championship week runs from 11 to 18 October 2026 in Kolkata, India, organised by Logic Masters India. The Sudoku championship itself takes place on the first two competition days, 12 and 13 October; the World Puzzle Championship follows later in the week.
Sources: WSPC 2026: official site and schedule
France publishes warm-up results on the road to 2027
September 29, 2026
France will host the World Sudoku and Puzzle Championships in 2027. The organisers published the results of a discovery contest on 29 September: in the Sudoku part, Timothy Doyle finished the six grids in 23 minutes and Adem Jaziri in 27; among new players, Régis Lamperrière scored 48 points and Myriam Papin 40.
Sources: WSPC 2027: results of the discovery contest
Sudoku as a reasoning test for language models
September 27, 2026
Sudoku also turns up in AI research. A preprint by Hongbo Chen, Guohua Lu, Ting Dang and Hong Jia trains a language model on intermediate solving states and reports 64.4% exact solve accuracy on the Sudoku-Extreme set with Qwen3-1.7B.
Sources: arXiv 2609.33149
Czech Sudoku Championship in Brno
September 19, 2026
The Czech Sudoku Championship took place on 19 and 20 September 2026 at the Institute of Mathematics and Statistics of Masaryk University's Faculty of Science in Brno, with individual, team and junior competitions.
Sources: Czech Sudoku Championship: official site
Sudoku as a case study in p-adic mathematics
September 13, 2026
Greg Baker's paper on encoding all-different constraints with signed p-adic residues uses standard Sudoku as an 81-coefficient case study. According to its arXiv record, it has been accepted for publication in the journal p-Adic Numbers, Ultrametric Analysis and Applications.
Sources: arXiv 2609.16063
