Sunday Surprise #3 – Spy Futoshiki

Today’s surprise comes from Tyler Hinman, five-time winner of the American Crossword Puzzle Tournament and author of Winner’s Circle Crosswords. I’ve had the pleasure of co-solving with Tyler — whom I call “Kid Crossword” when in “Dr. Sudoku” mode — on many puzzle hunts in recent years and we’ve had a number of good conversations on puzzle design. Total Masyu, which appeared again this Tuesday, for example was an idea that came up in one such chat from Tyler that I constructed for my blog.

As I heard from Tyler a few months ago: “Here’s a weird idea I had the other night while unable to sleep. … It’s inspired by the Spy piece in Stratego, which wins a battle if it attacks the highest-ranked piece (the Marshal), but loses under all other circumstances.” The concept was for Spy Futoshiki, the subject of today’s surprise, where the lowest value (1) is considered greater than the highest value (5), but all other inequalities obey normal ordering. It’s a clever idea and Tyler’s provided a very nice puzzle to demonstrate the change.

Futoshiki Variation by Tyler Hinman

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Spies among us

Rules: Insert a number from 1-5 into each square so that each number appears once in every row and column. Inequality signs between the boxes indicate the larger/smaller numbers, with the single exception that the number 1, the “Spy”, is considered larger than the number 5 if in adjacent cells.

Answer String: Enter the 1st column from top to bottom, followed by a comma, followed by the 5th column from top to bottom.

Solution: PDF

  • Scott Handelman says:

    Let’s just go one step further and do a rock-paper-scissors-lizard-Spock Futoshiki.

  • skynet says:

    6’54”

  • Avatar photo Grant Fikes says:

    I laughed when I saw the break-in. Excellent job, Tyler.

  • Steve says:

    I always thought that the spy wins when attacking any piece, and loses when attacked by any piece. But I guess that wouldn’t have any translation to Futoshiki.

    • Avatar photo drsudoku says:

      You are correct. I think Tyler’s point was about the special ability to get the highest value in an attack which, if we remove the “who attacks who” in this greater than/less than comparison sense, is the only essential point that remains about the Spy for Futoshiki.

      • Avatar photo Grant Fikes says:

        I’ve read both variations (the Spy only wins if it attacks the Marshall, and loses otherwise; the Spy wins if it attacks anything but a Bomb and loses otherwise). WikiHow even has an article that claims the Spy wins if the Marshall attacks it. Bleh. Rules for games I don’t own are complicated.

        I wonder if it’s like Monopoly where most people “know” the rules secondhand instead of from the official book of rules, and therefore it is common to get certain details wrong.

    • Tyler Hinman says:

      Actually, I’m quite certain my statement of the rules is correct. The PDF of the rules on Hasbro’s website backs me up.

  • chaotic_iak says:

    02:19. Y U NO HAS TARGET TIMES

    Wow, that’s a very interesting break-in. Nice variation.

  • I enjoyed the challenge, and I solved it, but based on the other comments I feel like I must still be missing something I should have seen.

    • Andrew Brecher says:

      Yeah, I think I missed the intended break-in, too. Basically I bifurcated at R1C3 and kept going until one path hit a dead end.

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