Most people meet sudoku as a quiet newspaper puzzle. For a few hundred solvers around the world it is also a competitive discipline, with national selection events, an online circuit and an annual world championship. This article explains where the World Sudoku Championship (WSC) came from, how a modern edition is actually run, who has won it, and what an ordinary player can learn from the way competitors prepare. Every fact below is taken from the sources listed at the end; where we could not verify something, we left it out.

A short history

The first World Sudoku Championship was held in Lucca, Italy, in March 2006, at the height of the global sudoku boom. According to a contemporary report in the Taipei Times, 85 contestants from 22 countries took part, and about 30 percent of them were women. The puzzles included classic sudoku as well as variants with extra regions, all solved against the clock.

The winner was Jana Tylová of the Czech Republic, a 31-year-old accountant who had been only ninth after the first round. Two Americans completed the podium: Thomas Snyder, then a chemistry graduate student at Harvard, and Wei-Hwa Huang, a software engineer at Google. Her advice to other enthusiasts was simple: practise more. She said she was solving for about two hours a day.

Since then the championship has been held almost every year in a different country under the umbrella of the World Puzzle Federation (WPF). Each edition is organised by a national member of the federation, and the national teams are chosen by the federation's local member organisations. A team competition was added in 2007, separate age-group titles for under-18 and over-50 solvers appeared in 2013, and since 2011 the WSC has usually been staged together with the World Puzzle Championship as a combined event (WSPC). There was no championship in 2020 or 2021: the edition planned for Shanghai in 2021 was cancelled because of the COVID-19 pandemic. The competition returned in 2022 in Kraków.

The WPF called the 2025 event in Eger, Hungary, the 18th World Sudoku Championship. The 19th edition is being held in Kolkata, India, in October 2026, hosted by Logic Masters India; its website lists 157 confirmed participants from 32 countries. At the time of writing its results had not yet been published, so the table below stops at 2025.

How the championship works

Formats change from host to host, but the basic shape has stayed stable. Over two or more days, competitors solve well over a hundred puzzles in a series of timed rounds. A typical round lasts between about half an hour and an hour and contains a mix of classic sudokus and variants with a points value for each puzzle. The 2026 instructions booklet is a good example of the current rules:

Individual rounds: ten rounds of 35 to 75 minutes. Points are awarded only for puzzles that are fully and correctly solved; there is normally no partial credit.
Time bonus: a solver who correctly finishes every puzzle in a round earns bonus points for each full minute left on the clock. A single minor slip (at most two wrong cells in one puzzle) can still earn a reduced bonus at the judges' discretion.
Team rounds: national teams of three or four members work together on large, interconnected puzzles. Individual scores are divided by four and added to the team rounds, so both parts matter for the team ranking.
Playoffs: the top eight solvers after the individual rounds meet in a knockout. In 2026 the quarter-finals use variants such as Killer and Disguised Queen, the semi-finals Odd and Even sudoku, and the final is a classic sudoku. Each duel gives 15 minutes and a single chance to submit, and the first correct solution wins.

The playoff format has always been dramatic. Thomas Snyder told The Stanford Daily that the 2006 final felt like “a weird game of Survivor”: nine players solved a puzzle each round and the slowest was eliminated until one remained. He lost the last puzzle, and he said that defeat motivated him to practise harder; he won the next two championships.

The variants you meet at a world championship

Classic sudoku is still the backbone of the event, but a large share of the points comes from variants. The 2026 booklet alone lists dozens of them, including:

Killer sudoku – cages with a given sum and no repeated digits.
Thermo sudoku – digits increase along a thermometer shape.
Arrow sudoku – the digits on an arrow add up to the digit in its circle.
Diagonal and irregular sudoku – extra diagonal constraints or jigsaw-shaped regions.
Anti-knight, non-consecutive, Kropki, XV and renban – rules about which digits may sit next to each other or a knight's move apart.
Samurai and other overlapping grids, plus newly invented rule sets that appear for the first time on the day.

Because some rules are new, organisers publish an instructions booklet with an example of every puzzle type a few weeks in advance. Reading it carefully is part of the preparation.

Individual world champions

The table lists every individual champion from 2006 to 2025, based on the WPF and the Wikipedia overview of results.

Year	Host city (country)	Individual champion	Champion's country
2006	Lucca (Italy)	Jana Tylová	Czech Republic
2007	Prague (Czech Republic)	Thomas Snyder	United States
2008	Goa (India)	Thomas Snyder	United States
2009	Žilina (Slovakia)	Jan Mrozowski	Poland
2010	Philadelphia (United States)	Jan Mrozowski	Poland
2011	Eger (Hungary)	Thomas Snyder	United States
2012	Kraljevica (Croatia)	Jan Mrozowski	Poland
2013	Beijing (China)	Jin Ce	China
2014	London (United Kingdom)	Kota Morinishi	Japan
2015	Sofia (Bulgaria)	Kota Morinishi	Japan
2016	Senec (Slovakia)	Tiit Vunk	Estonia
2017	Bangalore (India)	Kota Morinishi	Japan
2018	Prague (Czech Republic)	Kota Morinishi	Japan
2019	Kirchheim (Germany)	Ken Endo	Japan
2020–2021	No championship (2021 Shanghai edition cancelled due to COVID-19)
2022	Kraków (Poland)	Tiit Vunk	Estonia
2023	Toronto (Canada)	Dai Tantan	China
2024	Beijing (China)	Ming Letian	China
2025	Eger (Hungary)	Dai Tantan	China

Japan's Kota Morinishi holds the record with four titles (2014, 2015, 2017 and 2018). Thomas Snyder (USA) and Jan Mrozowski (Poland) have three each, while Tiit Vunk (Estonia) and Dai Tantan (China) have two; the WPF noted that Dai won back her title in Eger in 2025. In the team competition Japan, China and the Czech Republic have been the most successful nations.

Speed records exist outside the championship too. Guinness World Records lists Thomas Snyder's competition times of 1 minute 23.93 seconds for a “very easy” sudoku and 2 minutes 8.53 seconds for an “easy” one, both set at BookExpo America in Washington, DC, in May 2006.

What separates top solvers

Elite solvers rarely talk about secret techniques. The published material points to a few habits instead.

Volume of practice

Tylová's two hours a day in 2006 has already been mentioned. Snyder told The Stanford Daily that as a graduate student he was solving roughly a hundred puzzles a month, and that later, with less free time, he used puzzles as a morning warm-up: “I can do two puzzles in six minutes, feel that my brain has woken up and then go to work.”

Scanning and notation

In a 2025 talk published on his GM Puzzles blog, Snyder focuses on ways to scan and notate a sudoku, when to use each approach, and how to train for competitions while measuring whether you are actually improving. The underlying idea is useful for anyone: fast solvers do not try every technique on every cell. They scan in a fixed order, keep pencil marks minimal until they are really needed, and know which pattern is worth looking for at each stage.

Technique fluency and variant knowledge

Under time pressure there is no room to work out what a hidden single or an X-Wing looks like; recognition has to be automatic. In the same way, a solver who has never met a thermo or arrow puzzle loses minutes reading the rules. That is why competitors study the instructions booklet and practise unfamiliar variants beforehand.

Accuracy

Because one wrong digit usually means zero points for a puzzle and can cost the time bonus, checking matters as much as speed. Snyder's 2006 final shows how a single mistake can decide a title.

How to get involved

You cannot simply sign up for the WSC: each country sends a team chosen through its own selection. In India, for example, Logic Masters India ran four online rounds in 2025 followed by an in-person Indian Sudoku Championship in Kolkata on 1 June to pick the team for Eger. In Turkey, 17-year-old Can Erturan won the national selection in June 2025 and then finished second in the under-18 category in Eger, where the Turkish A team placed eighth.

The easiest entry point is the WPF Sudoku Grand Prix. In 2025 it consisted of eight online sudoku rounds (plus eight puzzle rounds), each lasting 90 minutes. You download the puzzles, solve them on paper and submit your answers online; participation is free and open to every level, and only each solver's best six rounds count. The top Grand Prix finishers meet in a playoff at the world championship.

How a regular player can practise

Solve a little every day. A regular routine with the daily sudoku builds the kind of scanning reflexes that competitors rely on.
Time yourself on graded puzzles. Use our sudoku puzzles by difficulty and note your times, so you can see real progress rather than guessing.
Understand difficulty. Our guide to the SE rating explains which techniques a puzzle requires, which helps you choose the right challenge.
Learn advanced patterns until they are automatic. Start with fish patterns in our article on the X-Wing and Swordfish technique.
Try variants. Even a few killer or thermo puzzles a week will make new rules feel less intimidating.
Check before you submit. Make it a habit to scan every row, column and box once at the end.

Whether or not you ever enter a qualifier, the champions' habits – steady practice, systematic scanning and careful checking – are the same ones that turn a frustrating puzzle into a satisfying one.

The World Sudoku Championship: History, Format, Champions and How Top Solvers Train