Author Archives: rob

Brief championship report: WSC and WPC 2019

The 28th WPC and 14th WSC took place in Kircheim, Germany last week. The outstanding results from my point of view were Ken Endo’s surprise win of the WSC individual competition, and Philipp Weiß’s amazing win over Ken Endo of the WPC individual competition. Congratulations! My own individual performance was rather disappointing, with offical ranks of 43 (sudoku) and 17 (puzzles), rarely feeling that I was puzzling at speed.

And then there was the WPC team competition, where Michael Ley, Hartmut Seeber, Philipp Weiß and I won the silver medal with a nominally weaker team than in past years, missing out on the likes of Sebastian Matschke, Markus Merker and the Voigt brothers. In a very exciting team playoff (for the players, at least – I don’t know how much the crowd saw), we came from behind to do well on the team puzzles, overtaking Japan and Slovakia and managing to hand in an intuited almost-solution to the final Slitherlink puzzle in the last seconds, giving new world champion USA a proper scare. They were a good half-way through their final Fillomino puzzle at that point – saved by the bell! Congratulations to all the teams, particularly team USA for a deserved win.

Some results can be found on the tournament website, though at the time of writing, the team playoff results are still missing.

I doubt I’ll analyse this championship in as much detail as last year, but expect a few of my preparation puzzles over the next few weeks. At this point I’d like to extend a big “thank you” to organizers and authors for a very well done set of competitions.

Puzzle 180: Geradeweg

I should be writing up my experience in Kirchheim from two weeks ago, where I managed to beat Ulrich Voigt to take my first German title. Instead, here’s a Geradeweg puzzle, to serve as an advertisement for the Puzzler’s Club contest at LMI next weekend. The contest will feature two puzzles of mine (a Geradeweg and a Checkered Fillomino), next to a number of great puzzles by other authors.

[solve online]

Puzzle 178: Times Zone

David Millar of came up with a neat new type recently with Times Zone. It’s a hybrid of latin square and loop puzzle, where the numbers inside the loop (in the “times zone”) form products while the numbers outside form sums. Check out the Intro to Times Zone for detailed instructions and a walkthrough. Here’s one I made, enjoy:

Rules Fill the grid with digits 1-6, so that each row/column contains each digit exactly once. Furthermore, draw a single loop along the grid lines that doesn’t touch or cross itself.

The loop divides each row/column into groups of digits. Each such group of digits corresponds to a number; it’s the product of these digits if the group is inside the loop, and the sum otherwise. Clues outside the grid describe the groups in that row/column in the correct order; an asterisk (*) stands for an arbitrary amount of groups, including no group at all.