TomTom by Thomas Snyder

TomTom by Thomas Snyder


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

Theme: Repeats upon Repeats Upon Repeats

Author/Opus: This is the 311th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard TomTom rules, using the integers 1-9.

Answer String: Enter the 4th row from left to right followed by the 6th row from left to right. Separate the entries with a comma.

Time Standards (highlight to view): Grandmaster = 22:30, Master = 35:00, Expert = 1:10:00

Solution: PDF; a solution video is also available here.

Easter Egg, and not a puzzle spoiler (rot 13): Did you notice gung gur zvqqyr 3k3 vf nyfb n inyvq chmmyr, whfg abg bar jvgu n “ercrngf” gurzr? Vg’f GbzGbzf nyy gur jnl qbja.

Note: Follow this link for other classic TomTom. If you are new to this puzzle type, here are our easiest TomTom to get started on. More TomTom puzzles can be found in The Art of Puzzles.

  • JuffoWup says:

    Beautiful puzzle! And a satisfying solve to boot.

    How difficult was this from a construction perspective?

    Bapr pbhyq fnl gur zvqqyr guerr ol guerr vf n qrtrarengr rknzcyr bs gur gurzr fvapr vg ercrngf mreb gvzrf!

    • Avatar photo drsudoku says:

      This took several hours to construct. I was lucky that one of the large rows/columns has some solvable cells without defining anything in the outer ring. So I built the new solving path around that seed, while still trying to get the full “repeat” theme to work including four identical clues in R1 and R9 (hard) with paired repeating clues in C1 and C9 (easy).

      It wasn’t built from the start to work with another 9×9 layer, and I would have done certain things differently if I had been intending for that. One hard bit is that this clue pattern is challenging to make unique (for example, the adjacent 5+ cages in R45C3 and R45C4, need to take a different set of 14 and 23 or the puzzle is non-unique and there aren’t a lot of cages that can force that to be resolved). I could have had the R45C4 cage repeat with R56C6 instead to not leave as many “uniqueness” traps in the grid.

  • SS says:

    I love these big, tough TomToms! Though I must have recently solved a few 1-8 versions recently, as I neglected to consider some of the arithmetic involving 9s, which screwed me up on a first attempt. Great puzzle.

  • LorenR says:

    I finally love this puzzle. It took me some multiple of the reported construction time over three starts. Usually, I can knock off a TomTom in good time but this one took me great effort to find the starting/continuation point(s). My final solution sheet has few in-grid marks and side helper calculations for 11, 8, 2, “2-“, 9, 6 and 4 only.

  • LorenR says:

    OK, I have now watched the video. I really appreciated the comment at the end about likely solving time. Please don’t attempt an 11×11. 😉

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