At SudokuCon, I brought together a lot of my stories and talks from 2006-2011 to tell my story of “How to Solve Sudoku Like a World Champion”. This video should tell you a lot about me and my journey to winning three world championships as well as some of unexpected things that go alongside that. The video should also (A) give you insights into ways to scan and notate Sudoku and when to apply them, (B) show you how to train for competitions and know you are making progress, and (C) offer up some other interesting ideas on geometry, sudoku construction, and more. On YouTube, there are many chapter marks to help explore the video for specific topics.

This week’s Friday Tapa was a tough one, with many questions both from readers and test-solvers on what the intended logic is. This post will answer that question completely.

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I knew when constructing puzzles for this past week that it would end up pretty tough across the board. I had certain themes in mind and when constructing for a particular goal you cannot always tailor the timing precisely. I believe — except for Monday’s puzzle — everything was rated for at least 5 minutes. It is probably asking too much to expect a full week to “feel perfectly balanced” when there are six different styles being presented.

So, while it may be impossible to avoid “hard” weeks in the future, this did seem an apt time to return to discussing some of these puzzles. I got a specific request to describe Saturday’s Battleships in logical terms, so that is what I’ll cover today.

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Tenth in a series with puzzle solving tips. This time with advice on Fillomino puzzles and hidden polyominoes.

Fillomino is one of my favorite puzzle styles, in part because it is one of the few where I think the author’s touch can come across in the puzzle in so many different ways. In the set of Fillominoes I’ve gotten from different authors, I think I can pick out some authors from others just based on how much they use visual patterns, one-option polyomino growth, crowding, counting, how well they conceal hidden pentominoes, and so on. While having a variety of puzzle constructors will improve most sections of The Art of Puzzles, Fillomino is hands-down in my mind the one where having many authors will have the greatest effect on quality.

I wanted to talk about one of my own constructing trends which I learned this week after writing 7 Fillomino puzzles (only a few that went online; some are going to GAMES and others are being saved). That is what I’ll call the “known unknowns”. The picture you should have in your head when considering a choice based on the hidden polyominoes you’ll leave behind. The contradictions in the “known unknowns” are the basis for the Saturday Fillomino.

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Ninth in a series with puzzle solving tips. This time with advice on Slitherlink and loop puzzles in general.

Even if you had a good time on the TIME Slitherlink, the following walk-through might offer you some new tips — besides just memorizing Slitherlink patterns — to get better at loop puzzles.

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Eighth in a series with puzzle solving tips. This time with advice on battleships puzzles, particularly missing clues and subs.

Solving Battleships is an odd experience for me. I think I want to enjoy them, but I’m not sure I ever really do very much. See, they were the first logic puzzle type I ever grew to love. But that means they also became the first logic puzzle type to bore me, and I’ve now been in the “bore me” stage for over half my life. And there is so much sameness in the Battleships you can find in the world right now. ~99% are randomly generated, ~99% give all of the outside clues which limits the challenge, ~99% solve by placing the largest ship(s) in the only possible spots and being good at bookkeeping of seas afterwards. As a member of the puzzling 1%, I am looking for something more. This week I tried to vary the formula a bit to make some more interesting — or at least different — puzzles.

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There is no Doctor’s Note this week.

Seventh in a series with puzzle solving tips. This time with advice on exploring unusual puzzle geometries such as the Saturday Sudo-Kurve.

When you’ve solved enough 3d Sudoku or Sudo-Kurve puzzles or other unique geometries (as in Sudoku Masterpieces), you’ve probably recognized there are sometimes cells or sets of cells that are much more constrained than others in the construction. This Sudo-Kurve grid, which I used in Sudoku Cup 3 and only one other time since, has some secrets to observe before getting too deep into any puzzle.

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Sixth in a series with puzzle solving tips. This time with advice on both solving and constructing skyscrapers puzzles.

I’ve gotten a lot of requests for tips on how to construct puzzles. I don’t offer many online as I have a monthly column in GAMES magazine that covers this and I don’t like competing with myself for less money. But Mike Selinker and I have improved on that content recently in turning our columns into a book, Puzzlecraft: The Ultimate Guide on How to Construct Every Kind of Puzzle. Please check it out.

This week, I thought I would give some insights into how I made this puzzle. Since I often construct a puzzle by thinking in the same way that I would solve the puzzle, the images below will show you both how I made the grid (and when I needed to use certain clues) and also how solvers likely completed the grid (and when they needed to use certain clues).

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Fifth in a series with puzzle solving tips. This time, with some advice on global constraints that arise in loop puzzles.

Some of you have asked why I don’t put “general tips” up before I post any puzzles. I find that learning how to solve puzzles is more interesting than reading how to do every single step. I won’t post a list of the top 20 Slitherlink patterns you should memorize, for example, on the rules and info page. Most of you would probably get more enjoyment figuring those out for yourself. But, after you’ve solved a challenge, I do like highlighting some of the things as constructor I tried to include, perhaps as a lesson for the future. This is what I will do this week with parity constraints for the Friday Masyu.

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Fourth in a series with puzzle solving tips. This time, basic steps to get through Cave puzzles.

While I’ve already written a good description of solving Cave (Corral) puzzles for the USPC, I’ve never drawn up some of the steps for more visual solvers. This week I hope to fix that by highlighting one of the more fundamental logic steps behind these puzzles.

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