Sudoku World Record 2018

Sudoku World Record Competition 2018 took part in the World Sudoku & Puzzle Championships 2018 being held in Prague in the Czech Republic.

Qualification rounds

First qualification round  was held on Monday evening 5 November after the first competition day of World Sudoku Championship 2018 (WSC2018). The fastest, Shiyu Chen from China, solved three qualification puzzles in 3 minutes and 20 seconds. Jan Mrozowski from Poland finished three seconds after Shiyu. Takuya Sugimoto from Japan completed trio qualifiers for the final round with his time a bit over 4 minutes. Initially third,  Cheran Sun from China, finished her puzzles with one small mistake and therefore could not become the third quailifier.

Second qualification round followed the first one, unfortunately, the printed mistake in the competition booklet would affected the competition itself and thus second round was cancelled.

On Tuesday evening 6 November third qualification round substituted cancelled second round with selection procedure of trio qualifiers for the final round. And again Chinese player took the first spot. Shiyao Wang finished in 3 minutes and 13 seconds, followed by her two teammates Letian Ming and Cheran Sun finished not long after her.

As the unlucky one could feel Kota Morinishi that finished in both qualification rounds on the 4th place, i.e. first spot out of the final. On the other hand, Kota won WSC2018 and all three WSPC2018 medalists took high places in the qualification rounds that suggets the best sudoku players belong to the fastest solvers of classic sudoku.

Competition booklets for qualification rounds

Final round

Final round was planned on Wednesday evening 7 November in the hotel foyer. Seven big boards (flipcharts) were prepared for 6 qualifiers and the last, seven spot took reigning world record holder Jakub Ondroušek from hosted country. Boards were equipped with large pieces of paper (A1 size) used for filling in two final sudoku puzzles to break sudoku world record from 2010. Seven finalists represented a battle between Asian younth (Shiyu, Shiyao, Letian, Cheran and Takuya) and two more experienced guys from Europe (Jakub a Jan) with 8 individual medals from WSC. A comparison of their classic sudoku skills had already been realized two days before in the 1st round of WSC2018 consisting of 13 classic sudoku puzzles. Except one, all of them fihished amongst the best 10 competitors in this round (see table).

Jakub	Letian	Jan	Shiyu	Shiyao	Cheran	Takuya

Jakub	Letian	Jan	Shiyu	Shiyao	Cheran	Takuya

Back to the final, after warmimg up everything was prepared for the first attempt to break Sudoku World Record time from 2010, 1 minute and 25 seconds. Taking in account the pre-testers times we believed that could happened. Three, two, one, START. 

Video from the final round on YouTube (click on image)

Letian finished the first puzzle apparently as the fastest, but did not raise his hand immediately to get the sign for referees that he is finished. Then Shiyao in time of 59 seconds completed her puzzle, few seconds later raised the hand also Letian. Another three finalists - Shiyu, Jakub and Jan were done in time under pace of the World Record. Incredible beginning. Audience was impresssed in spite of the fact that almost everybody knew what the best players are capable of. To sum up first puzzle, Cheran and Takuya had incorrect solutions of their puzzles. 

Second puzzle looked thougher than first one. No worries for Shiyao, she raised her hand after 54 seconds and became new World Record Holder. Her time was confirmed by the referees to final 54,44 seconds. Jakub finished 25 seconds later, then Letian, both still under pace former world record. Cheran and Takuya also succeeded and thus all the competitors closed the final with valid solution. Congratulations to all.

All correct solutions were ranked after second attempt, total eight achieved solution times were better than former World Record that Shiyao cut by 30 seconds. It should be noted that solving on flipchart is different and slower than solving on paper and not everybody does cope with it. Shiyao did, she is Sudoku World Record Holder.

Puzzles from the final

Full Czech version of the story