Ah, the beloved WPC, and the reason why I went to Beijing. This year Canada’s A team consists of Byron, Derek, Dave, and I, the same team we had back in 2009 in Antalya, Turkey.
Round 1 was a team round where each team was given 8 puzzles: LITS, doubleback, starbattle, only four digits, corridors, masyu, binaire, and yin and yang. The twist is that the 10×20 grid is broken up into a 10×13 and a 10×7 section, and we have to match and solve them. Before the competition started, we decided on who to handle which puzzle, and I took Masyu and LITS. In the beginning, we simply started solving the 10×13 fixed grids, then started to look for matches. There were two tops that clearly could not be Masyu, but the other 2 were inconclusive. I then started looking at the LITS and noticed that 3 of the 4 top grids have regions of size smaller than 4. That meant that I got a LITS match and started solving it. The next bit was kind of a blur but I managed to solve the LITS, and the rest of the team was similarly able to figure out and solve which was the double back loop, star battle, and only four digits. Byron then worked out which was the corridor. The Binaire was also inconclusive, so I thought that the break-in puzzle was yin and yang. It turned out I was wrong, and that the Masyu was the break in. However, the contradiction was only evident when you complete the top grid and combine it with the bottom. As I was figuring that out, Dave started solving both of the remaining grid as binaire, and found no contradiction, which meant that we had to figure out which was the Yin and Yang. We managed to pull that one off, and solved everything with less than 1 minute left on the clock. Luckily for us, we made no mistakes, and got the 2000 points.
Round 2 was the classics, a round that served me well. Most of the puzzles on this round were fairly typical, without too many twists and turns. The thermometer was funny, but easy, while the yajilin had me staring at it in shock as it was nothing but zeroes. From what I heard later, the clues were placed on a checkerboard like pattern that forces all the squares not pointed at by a zero must be black. I didn’t notice that, but was able to break into it with minimal trial and error regardless. In the end, I solved everything except for the domino halves and the sudoku +/-4. Since when did sudoku +/-4 become a classic puzzle anyways?
Round 3 was the round feared by everybody, including some of the top solvers. According to Palmer’s blog, Ulrich asked the organizers whether he could skip this round instead of one of the next 4 rounds instead. Just before the round, Derek came in with a tip of drawing out which segment is possible for which digit, which I promptly copied and used. In the end, I was able to do the masyu, the digital paint, and the price tags. I solved the first skyscraper, but botched the other and was unable to fix it. My biggest regret for this round was that I foolishly decided to skip the digital mess, despite the fact I saw that the digits can be broken up into groups somehow.
Round 4-7 were rounds designed by puzzle authors from 4 different countries. Furthermore, each contestant must pick a round to skip so that the contestant of each team all skip a different round. Byron picked round 5, I picked round 7, Derek picked round 6, and Dave was stuck with round 4. In retrospect, that may not have been the wisest decision, as I did horrible in round 4, compared to the rest of the rounds.
I hated the Dutch Round 4 after the competition, despite of me liking it the best before going into it. The so-called 4 point tents puzzle took me over 20 minutes, and I still did not manage to solved it. On the plus side, after taking some hints from Byron, I managed to get the 8 point neighbours, and a few guesses netted me the masyu battleships. The pento fences was surprisingly easy as well. The rest of the puzzles I did though were low pointers, which contributed to my low score for this round.
Round 5 was the Indian round, which I was most worried of before the afternoon started. It was not as bad as I imagined as I grabbed the gapped kakuro, tapa, slalom, heyawacky, and a couple of low pointers to get my a score of 49. While I did not noticed it at the time, the puzzle was designed so that reading across the puzzles you can get the message “ENJOY WPC 22 INDIAN ROUND”, which was very nifty.
Round 6 was the US round, which was very interesting. You are first given a standard puzzle, then a related puzzle that replaces some elements with a doubled up version. For example, they replaced the black cells of the Yajilin and the Kuromasu by blocks of size 1×2. Furthermore, the 2 puzzles further linked by keeping some elements of it, such as the digits common. While the puzzles themselves were neat, they were also brutal, as one of the designer was Palmer. In particular, the 2 Nurikabe was absolutely nasty, though I managed to get them both. I also did the 2 Yajilin and Shikaku, as well as a few other classic puzzles.
Round 7 was the Serbian round that I was supposed to skip. However, we were allowed to stay in the contest hall and do the puzzles as long as we do not hand it in. As it was the last round of the day, I saw no reason not to. My performance for this round was not specticular, as I the only high pointers I was able to do were the tapa and the Easy as ABCDE no touch. The Arukone (numberlink) turned out to be not unique, but that did not really matter.
This concludes day 1 of the 22nd WPC. After dinner, there was supposed to be a Jackie Chan movie of some sort. I didn’t stay to watch it, and from what I heard, it wasn’t very good. Furthermore, the results of round 1-3 were out, and I was tied with Byron. At least, until that I spotted a counting error in round 2 that netted me an extra 50 points. While not delighted about my afternoon performance, I am still fairly satisfied with my overall performance in the day.