Sudoku World Championship 2012

There were 13 sudoku puzzles, and 12 of them had to be connected at an angle, and the solution provided a clue for the 13th, which you had to figure out yourself. Each sudoku was worth 15 points, the last 13th was worth 20 points. We finished 9, and in my opinion, we had very good teamwork and a result of 135 points, which gave us 10th place.

For the round, 6 sudokus and 18 little piglets were given. In each sudoku, 3 piglets had to be placed and the sudoku solved. It was a rather difficult round, but we managed to solve 3 out of 6 and collect 75 points, which gave us somewhere between 9th and 13th place. So, the team rounds were very successful.

As mentioned, I came in 3rd place in the preliminary rounds. The points table looked like this: 1. Kota Morinishi /Japan - 503 2. Jan Mrozowski /Poland - 456 3. Tiit Vunk /Estonia - 429 4. Jakub Ondroušek /Czech Republic - 420 5. Hideaki Jo /Japan - 415 6. Bastien Vial-Jaime /France - 409 7. Chen Cen /China - 396 8. Rohan Rao /India - 385 9. Yuhei Kusui /Japan - 379 10. Jin Ce /China - 367 __/110. Jaan Laks - 126 75/111. Villem Mesila - 125 76/113. Triin Melnik - 118 81/120. Margit Ool - 109 __/130. Allar Padari - 87 Allar and Jaan participated unofficially, that's why I showed my teammates the results in both categories. Allar and Jaan were members of the logic World Championship team and decided to come here for sudoku and participate unofficially. In the team classification, Estonia was 14th, which is the second best result ever from the sudoku World Championship. The best 13th place so far was 1 point away :)

The top 8 from the preliminary rounds qualified for the finals. The final was played on a playoff basis, with 1:1 matches and the winner advancing. The quarterfinals were contested by 1st and 8th place, 2nd and 7th, 3rd and 6th, and 4th and 5th. The idea was apparently that the best of the preliminary rounds should have the greatest chance of advancing. This valued the results of the preliminary rounds. In addition, the competitor in front was given the advantage of choosing 2 sudokus to solve in each match. The opponent could choose one sudoku. The selection of sudokus was such that the tasks were divided into three containers: in the first, only easy and medium classics, in the second, difficult classics and more classic alternatives, and in the third, alternatives. First, the competitor with the best ranking chose a sudoku of his choice from two different containers, and then the opponent chose one sudoku from the one that had not been chosen. The sudokus were solved in turn. The solution looked like this: two boards were placed on the stage in front of the hall, where a large Sudoku was hung for each competitor. When the competition began, markers were handed out and the solution began. When the solution was in hand, the competitor raised his hand, turned his back on the boards and waited for the judges' decision. If the solution was wrong, there was a 1-minute penalty and then the opportunity to correct it was given. Matches were played to 2 wins.

First, the quarter-final 1-8 was played: Kota-Rohan. The first sudoku was the Special Shaped one chosen by Kota from the 2nd container, and then the average classic one chosen by Rohan from the 1st container. Kota won both and was left waiting for his opponent in the 4-5 quarter-final. Then came the quarter-final 4-5: Jakub-Hideaki, the result of which was quite difficult to predict, because these were two very tough solvers. First, it was necessary to solve the Sudoku Differences chosen by Jakub, where all adjacent numbers with a difference of 5 are marked with a small number "5". The competition was quite even, but Hideaki managed to take the first point here. It should be noted that Jakub is an excellent solver of classic sudokus, and Hideaki is especially excellent at solving alternatives. Apparently, Jakub's strategy was to choose the variant in which he might have the greatest chances. The classic choice is left to Hideaki, because he knows them anyway. The second sudoku was Smurf sudoku, where in the same sudoku there were marked places that had to be the same, and Jakub solved it with amazing speed. Hideaki had barely half of the grid filled. It turned out, however, that Jakub had made a mistake. Jakub waited a minute, then 2 minutes and could not find where he had made a mistake. Finally, Hideaki finished and it turned out that Hideaki also had something rotten. As a result, it was announced that the judges had been given a faulty check sheet and in fact Jakub's solution was correct. An extremely big oversight by the judges. Jakub threw the marker away and could not believe it all. This put him in a rather difficult situation mentally, in my opinion. The last sudoku was Pinocchio, which Jakub chose, but which Hideaki was able to solve faster, and thus Hideaki's Semi-Final against Kota. Next up was the Quarter-Final 3-6: or me vs. Bastien. Since I had a better position, I could make a choice and decided to first choose the outsides sum sudoku in the third container. The reason was, firstly, that I had practiced it quite a lot at home before and secondly, Bastien had a somewhat worse Math round than me. For the last sudoku, I chose the diagonal, which should be one of my trump cards in case the score remained 1:1. Bastien had no choice but to choose the average classic. When I started solving, it was quite unusual to solve in front of such a large table. In order to see the whole picture, I had to take a step back. Fortunately, it is a fairly locally solvable sudoku and I was very narrowly able to outdo my opponent and collect the first point. When I was told that I had won a point, my opponent had actually already finished and raised his hand. Second came the classic, which I was definitely hoping to win, but apparently I couldn't get used to this large table and at the very beginning I couldn't see the simple things several times. The opponent deservedly picked up his point. The entire French team stood up and expressed appreciation to their representative. Thirdly, the diagonal sudoku came and I made it my goal to focus more on seeing the overall picture of this diagonal sudoku. It paid off and was a sure win for me and I was waiting for my opponent from the match between Jan Mrozowski and Chen Cen. Finally, the quarter-finals 2-7, where Jan definitely won both the Star Product and the average classic sudoku. In the Star Product, some cells in each row and column are marked with a star, and the product of the numbers in the cells with a star at the end of the row and column is given.

Since Jan was in a better position, he got to choose. The choices were Little killer and TNT (2 7x7 special shapes together at the corners). I had to choose between easy or medium classic - I chose easy classic. First, the Kota-Hideaki semi-final was played, and Kota won it 2:0. Is the class difference really that big? In any case, Kota won the Hard and Easy classic by a landslide. So Kota in the final. My first sudoku was Little killer. For the record, Jan is very strong in mathematical variants and I had no chance of beating him in this. 1:0 to him and I had most of the sudoku blank. Next came the easy classic I chose. When I finished it, I quickly raised my hand and turned my back - while Jan was still solving. Looking at the audience, however, it was clear that they were discussing and explaining something. Jan finished it within that minute and received confirmation that his solution was correct. When I turned my face towards the sudoku, I saw two empty squares in my solution. Well, I couldn't just take a quick look to see if everything was resolved. This meant another loss for Jan and a place in the 3rd place match. If we had won, we would have had the opportunity to offer Jan a competition in the 7x7 combined special shapes, which could have been a pretty interesting opportunity to reach the finals. But unfortunately, we had to give up our place so easily with such stupidity.

In this match, my ranking was higher, and knowing that Hideaki is a very good alternative solver, I decided to leave him only the easy and medium classic. I chose distance sudoku first (in it, each row and column has numbers in the form 4-7:5, which means that 4 and 7 are 5 squares apart in that row). The second was essentially a choice between overlapping sudoku and hard classic. I don't know why, but I chose overlapping sudoku. In hindsight, hard classic would probably have been a better choice. Hideaki won the first match. I didn't have much left to solve when he finished, but he still showed good speed in it. In itself, he branched out quite normally for me, but obviously he branched out a little faster. The second easy classic was faster for me and before I raised my hand, I took a step back and checked that there were no empty squares. There were no empty squares and I raised my hand. However, it turned out that there was still some mistake. But since Hideaki couldn't finish, I was given the opportunity to find a mistake and in the bottom row there was a 9 and a 5 swapping. I fixed it and the score was 1:1. LATER it turned out that Hideaki had also messed up a bit while I was serving a 1 minute penalty and looking for a mistake. The third one was overlapping sudoku. Hideaki had a solution tactic for that and I had to accept defeat again, and I didn't seem to have much left to solve. I believe that if I had chosen the difficult classic, I would have had better chances - but who can say that before the competition. The result was still an excellent 4th place. I don't regret anything and I'm also happy with my performance, except for those 2 mistakes. One of them, however, allowed me to take the win.

In the final between Kota and Jan, the game was played to the best of 3. So first Kota chose 3 sudokus (1 from each container) and then Jan 2 (from different containers). The order of solving was as I remember it: Kota chose Diagonal irregular Jan chose KenKen Kota chose Light classic Jan chose TNT (2 x 7x7) Kota chose Sudoku Wheels, where there were circular shapes placed in the sudoku, each shape had 4 numbers. Then you had to turn the wheels to find the correct position for each wheel and solve the sudoku. Diagonal irregular was a real mess. Both opponents made mistakes during the solution, and since the marker could not be erased, but a different color marker could be used, they started to color the numbers there with several colors and it got quite confusing. After a long struggle, Jan managed to take the first point. Second was Kendoku, which is like a killer, but the box contains multiplications, additions, divisions and subtractions. Jan is strong in math, but Kota still managed to take his first point against Jan. The score was 1:1. The easy classic definitely went to Jan, the score was 2:1. While solving TNT sudoku, it seemed that Kota's brain had crashed, and there was no way he could come up with the solution. Apparently, the special diagonal shape, which took a lot of energy, played a role, and probably also Kendo, where quite a lot of thinking is needed to place most of the numbers. Jan won that too, and became the world champion.

After the finals, we were taken on a tour of Rijeka, where we visited the castle and a couple of churches. Then we were given a couple of hours to walk around the city (apparently all the sudokus were bought from the surrounding shops, because if 150 sudoku enthusiasts are let loose on one street, then what else can you expect?). Finally, we went to a 4* hotel for dinner, where the award ceremony was also held. The room was very small, and I think half of the people were in another room. There was a large pole shining in the middle of the room, and the award ceremony was held behind this pole. 80% of the people were sitting at their tables, because there was no hope of seeing anything. The remaining 20% were struggling in the narrow aisles and trying to get to the spot to take a picture. An absolute big oversight by the organizers. It could just as easily have been held in the middle of a nightclub dance floor, which is packed with dancers. That's how the Sudoku World Championship 2012 was.

Very exciting reading..You gained a lot of experience and I have no doubt that next year you will return with a medal. (I don't mean bronze here :P) but where was Snyder?