Tag Archives: number place

Farewell, Maki Kaji.

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maki kaji 1

When you get right down to it, the puzzle world isn’t all that big. There are a few names that everyone knows, and plenty of names that people should, but generally don’t. And sadly, too many of those names aren’t celebrated until after they’re gone.

Maki Kaji is one of those names you should know.

He passed away recently, and different articles and obituaries called him everything from “puzzle enthusiast” to “Sudoku creator,” but the title he most deserves is the one he put on his business cards: Godfather of Sudoku.

Honestly, he’s one of the three most important people in the history of Sudoku.

Howard Garns is credited with creating Number Place for Dell Pencil Puzzles and Word Games in May 1979 (though a French variant of the puzzle appeared in the newspaper La France in the 1890s). Wayne Gould stumbled upon Sudoku puzzles in a magazine, then designed a generation program and sold it to the Times in London, kickstarting the craze in the UK that spread elsewhere.

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[Maki Kaji at Brazil’s first national Sudoku competition in São Paulo in 2012.]

But it was Maki Kaji who championed the puzzle all over, using it in his puzzle magazine Nikoli starting in the early 80s, then taking advantage of the UK boom and selling it in dozens of countries. (Gould didn’t have the resources, so many newspapers and publishers came to Maki Kaji for them.)

The name Sudoku came from him. (In American puzzle magazines, it was Number Place or To the Nines.) Originally the puzzle was called Suuji wa dokushin ni kagiru, or “numbers should be single,” before taking the suggestion to shorten it to Sudoku.

Of course, despite his close association with Sudoku, Maki championed puzzles in all forms. He founded Nikoli (also known as Puzzle Communication Nikoli) with two school friends in 1980, four years before adding Sudoku to its roster of puzzles. It was Japan’s first puzzle magazine!

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One of the goals of Nikoli was to feature what they called “culture independent” puzzles, meaning puzzles that didn’t rely on a specific language or alphabet. (Talk about accessibility!)

“When we create our puzzles, we want people to enjoy them and not feel stressed by them,” he said.

Because of this culture-independent style, Nikoli was famed for its many logic puzzles, because they relied less on words and more on numbers, symbols, and elegant grid positioning. Popular puzzles included familiar ones like Sudoku and Kakuro, as well as less familiar puzzles like Nurikabe and Hashiwokakero.

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“I don’t want to just be the godfather of Sudoku,” Maki said. “I’d like to spread the fun of puzzles until I’m known as the person who established the puzzle genre in Japan.”

One of his key tools was a section in Nikoli that invited readers to submit their own ideas for puzzles. It quickly became the most popular part of the magazine. Readers submitted new puzzles, which other readers then refined and expanded on. Nikoli is credited with introducing hundreds of new logic and number puzzles to the world through this puzzle-loving fan-fueled pipeline.

Of course, even the Godfather of Sudoku ventured into crosswords from time to time. In fact, in 2017, it was reported that he published the world’s largest ever crossword, with 59,365 across clues and 59,381 down clues on a printed grid 30m long, kept in a scroll.

Go big or go home, I guess.

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[Constructor Peter Gordon (and his Sudoku license plate) with Maki.

Maki stepped down as president of Nikoli just last month, and the company released this statement in response to his passing:

Kaji-san came up with the name Sudoku and was loved by puzzle fans from all over the world. We are grateful from the bottom of our hearts for the patronage you have shown throughout his life.

But, naturally, it takes a puzzler to truly honor a puzzler, and I think Thomas Snyder (aka Dr. Sudoku, no slouch himself when it comes to the famed number puzzle) offered the perfect tribute on his Art of Puzzles website:

A wordoku puzzle dedicated to Maki Kaji.

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The puzzle world is a far richer and more varied place thanks to the creativity, hard work, and passion of Maki Kaji. You probably didn’t know his name before. But hopefully, you’ll remember it now.

Farewell, Maki. Thank you for bringing so many new eyes to the world of puzzles.

[Source links: Kotaku, The Guardian, Wikipedia.]

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Crossword History: An Updated Timeline

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Back in 2013, we created a timeline of events from crossword history as part of our celebration of the hundredth anniversary of the crossword.

Although 105 isn’t as prestigious as 100, and the anniversary is technically tomorrow, we thought we’d honor the day this year by updating our comprehensive look at the long (yet surprisingly short) road it took to get to that marvelous centennial!

So, without further ado or folderol, we proudly present:

A Brief History of the Crossword (Updated)

16th – 11th century BC

Inscriptions from New Kingdom-era Egypt (Eighteenth to Twentieth Dynasties) of horizontal and vertical lines of text divided into equal squares, that can be read both across the rows and down the columns, are made. These inscriptions are later referred to by Egyptologists as “Egyptian crossword puzzles.”

19th century AD

Rudimentary crosswords, similar to word squares, begin appearing in England, and later elsewhere in Europe.

June 22, 1871

Future inventor of the crossword, Arthur Wynne, is born.

March 23, 1897

Future New York Times crossword editor Margaret Farrar is born.

February 25, 1907

Future New York Times crossword editor Will Weng is born.

December 21, 1913

The New York World publishes the first crossword, invented by Liverpool journalist Arthur Wynne. (The puzzle is originally known as a word-cross.)

January 6, 1916

Future New York Times crossword editor Eugene T. Maleska is born.

1920

Margaret Farrar is hired by The New York World as a secretary, but soon finds herself assisting Arthur Wynne with proofreading puzzles. Her puzzles soon exceed Wynne’s in popularity.

Colonel H.W. Hill publishes the first Crossword Dictionary.

1923

Margaret Farrar revises the cluing system for crosswords, sorting them into “Horizontal” and “Vertical” clues by number. (It wouldn’t be until the 1940s that the more familiar “Across” and “Down” terminology became the norm.)

1924

Margaret Farrar publishes the first book of crossword puzzles under contract for Richard L. Simon and Max Schuster, “The Cross-Word Puzzle Book.” It was an instant bestseller, launching Simon & Schuster as a major publisher. (Additional information available below the timeline.)

The Daily Express, founded in 1900, becomes the first newspaper in the United Kingdom to carry crosswords.

Crossword-themed novelty songs hit the airwaves as the puzzle craze intensifies, most notably “Crossword Mama, You Puzzle Me (But Papa’s Gonna Figure You Out).”

The Amateur Crossword Puzzle League of America, a self-appointed group of puzzle enthusiasts, lobbies for rotational symmetry in crosswords, which becomes the standard.

Solver Ruth Franc von Phul becomes a minor celebrity after winning The New York Herald-Tribune’s National All Comers Cross Word Puzzle Tournament at the age of 20. (She would win again 2 years later.)

January 15, 1925

“Felix All Puzzled,” the first animated short to feature a crossword, is released.

February 2, 1925

The crossword-fueled musical revue “Puzzles of 1925” opens on Broadway. It runs until May of 1925.

February 15, 1925

Disney releases a crossword-themed animated short, “Alice Solves the Puzzle.”

1926

The cryptic crossword is invented by Edward Powys Mathers, who publishes under the pseudonym Torquemada. He devises them for The Observer newspaper.

First reported instances of Braille crosswords, as newspapers mention Helen Keller solving Braille crosswords and recommending them to the blind.

1931

Dell Puzzle Magazines begins publishing.
(Dell Publishing itself was founded in 1921.)

1941

Dell Pocket Crossword Puzzles first published.
(The magazine continues to this day.)

February 15, 1942

The New York Times runs its first Sunday edition crossword. (Additional information available below the timeline.)

June 2, 1944

Physics teacher and crossword constructor Leonard Dawe is questioned by authorities after several words coinciding with D-Day invasion plans appear in London’s Daily Telegraph. (Additional information available below the timeline.)

1950

The crossword becomes a daily feature in The New York Times.

August 26, 1952

Future New York Times crossword editor Will Shortz is born.

1968

Lyricist Stephen Sondheim begins creating cryptic crosswords for New York Magazine, helping introduce Americans to British-style crosswords.

1969

Will Weng succeeds Margaret Farrar as the second crossword editor for The New York Times.

1973

Penny Press is founded.

1977

Eugene T. Maleska succeeds Will Weng as the third crossword editor for The New York Times.

1978

First year of the American Crossword Puzzle Tournament, later featured in the documentary Wordplay. 149 contestants compete for the title in the first national crossword tournament since the 1930s.

1979

Howard Garns creates the modern Sudoku puzzle for Dell Magazines (under the name Number Place), the first pen-and-paper puzzle to rival the crossword in popularity (though this spike in popularity would occur decades later under the name Sudoku).

June 11, 1984

Margaret Farrar, while working on the 134th volume in Simon & Schuster’s crossword puzzle book series, passes away.

1993

Will Shortz succeeds Eugene T. Maleska as the fourth crossword editor for The New York Times.

November 5, 1996

One of the most clever and famous crosswords of all time is published, the election-preceding crossword where either BOB DOLE ELECTED or CLINTON ELECTED could read out, depending on the solver’s answers.

1998

The Wall Street Journal adds a crossword to its newspaper, and Mike Shenk is appointed editor.

June 23, 2006

Wordplay documentary hits theaters, featuring celebrity solvers of crosswords as well as the participants and organizers of the 2005 edition of the American Crossword Puzzle Tournament.

February 29 – March 2, 2008

Thanks in part to the Wordplay documentary, the American Crossword Puzzle Tournament outgrows its previous setting and moves to Brooklyn.

June 6, 2008

Matt Gaffney launches his Weekly Crossword Contest (MGWCC).

August 2008

Lollapuzzoola, a crossword-solving tournament with a more tongue-in-cheek, freeform style, launches in Jackson Heights, New York.

October 6, 2008

Patrick Blindauer’s famous dollar bill-inspired crossword puzzle is published.

2009

The city of Lvov, Ukraine, creates a crossword that spans an entire side of a 100-foot-tall residential building, with clues scattered around the city’s major landmarks and attractions. It’s awesome.

October 11, 2011

PuzzleNation.com goes live.

June 2012

David Steinberg launches the Pre-Shortzian Puzzle Project, designed to compile a complete database of every New York Times crossword.

August 13, 2012

PuzzleNation Blog is launched.

June 14, 2013

Matt Gaffney celebrates five years of MGWCC,
stating that MGWCC will run for 1000 weeks
(which puts the final edition around August 6th, 2027).

December 21, 2013

The Crossword officially turns one hundred years old.

Additional information:

1924: The publishing house Simon & Schuster, agreed to a small (3,600-copy) run of a crossword puzzle book, prompted by founder Richard L. Simon’s aunt, who wanted to give such a book to a friend. It became “a runaway bestseller.”

In no time the publisher had to put the book back on press; through repeated printings, it sold more than 100,000 copies. Soon a second collection followed, and then a third and a fourth. In 1924 and 1925 the crossword books were among the top 10 nonfiction bestsellers for the year, besting, among others, The Autobiography of Mark Twain and George Bernard Shaw’s Saint Joan.

February 15, 1942: The New York Times initially regarded crosswords as frivolous, calling them “a primitive form of mental exercise”; the motivating impulse for the Times to finally run the puzzle (which took over 20 years even though its publisher, Arthur Hays Sulzberger, was a longtime crossword fan) appears to have been the bombing of Pearl Harbor.

In a memo dated December 18, 1941, an editor conceded that the puzzle deserved space in the paper, considering what was happening elsewhere in the world and that readers might need something to occupy themselves during blackouts. The puzzle proved popular, and Sulzberger himself would author a Times puzzle before the year was out.

June 2, 1944: The words Omaha (codename for one of Normandy’s beaches), Utah (another Normandy beach codename), Overlord (the name for the plan to land at Normandy on June 6th), mulberry (nickname for a portable harbor built for D-Day), and Neptune (name for the naval portion of the invasion) all appeared in Daily Telegraph crosswords during the month preceding the D-Day landing.

This has been attributed to either an incredible coincidence or Dawe somehow overhearing these words (possibly slipped by soldiers involved) and incorporating them into puzzles unwittingly.

Do you have any suggestions for additions for our Crossword Timeline? Let us know in the comments section below! We’d love to hear from you!

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Other puzzles you might not know! (Volume 3)

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In previous editions of this series, we’ve presented some new puzzles for crossword devotees and Fill-In fans to try out. Today, let’s turn our attention to Sudoku enthusiasts.

Now, before we talk about other types of puzzles, there are numerous Sudoku variants to choose from, if you’d like just a little twist on the familiar Sudoku formula. In fact, I did an entire blog post about them, as well as posts about new variants like Will Sudoku and Pentdoku Puzzles!

There are a few lesser-known number-placement puzzles out there that might scratch your puzzly itch if you’re a Sudoku fan: Futoshiki and Beehive Hidato.

[Futoshiki image courtesy of PuzzleMagazine.com.]

Futoshiki will seem fairly familiar, since the row and column rules of Sudoku are in effect. But you have an additional placement rule to consider: the less than/greater than signs in the grid, which indicate where to place lower or higher numbers in the grid. (Futoshiki translates to “not equal” in Japanese.)

[Hidato image courtesy of TheGuardian.com.]

Beehive Hidato eschews the traditional Sudoku row/column system of the deduction in favor of chain-placement of numbers in its hexagonal grid. Your goal is to fill every cell in the grid by filling in the missing numbers between 1 and the highest number. So, instead of placing the same numbers in every row and column, you’re placing a different number in each cell, forming a single chain from 1 to the last number.

The cell containing the number 1 must neighbor the cell containing the number 2, and the cell containing the number 2 must neighbor the cell containing the number 3, and so on, all the way around the grid.

If you’re looking to go a little farther afield and leave numbers behind, I’ve got you covered.

After all, some people tend to think of Sudoku as a math puzzle, but it’s really not; it’s more of a deduction and placement puzzle. You could check out not only Fill-Ins, but also all the puzzles I’ve previously recommended for Fill-In fans. That’s a great place to start.

You could also try your hand at Brick by Brick.

[Click here or on the grid for a larger version.]

Brick by Brick puzzles are a terrific bridge between placement puzzles and crosswords, using aspects of both. You’re given the complete first row of a crossword, and all of your clues, both across and down.

But, instead of the black squares you’d normally rely on to help guide you through answering those clues and placing your words, you’ve got 3×2 bricks filled with letters and black squares, a scrambled jigsaw puzzle to reassemble.

Here you can use your deductive Sudoku skills to place black squares and entire bricks into the grid as you apply crossword-solving skills toward answering the across and down clues, working back and forth between the two to complete your grid, assembling chunks of answer words as bricks fit neatly together.

And if you prefer quote puzzles to crossword puzzles, there’s always Quotefalls.

[Click here or on the grid for a full page of Quotefalls.]

Quotefalls gives you all of the letters in a given quote, plus the black squares that separate each word from the next. But it’s up to you to figure out where in each column to place the letters above so that the quotation reads out correctly.

Sometimes that’s easy, like in the fourth column of puzzle 2 above. Since there’s three black squares and only one open square, you know exactly where that E will go. Seedling letters like that can go a long way toward helping you fill each word, and eventually, the entire quote.

It’s a different form of deduction, but one not too terribly far from the number-placement solving of Sudoku.

Any one of these puzzles could add some welcome variety to your puzzle solving, while still honoring the style and play inherent in your favorite puzzle. Give them a shot, and let us know how you like them.

Next time, we’ll be tackling recommendations for Cryptogram fans, but if you’ve got puzzle recs for your fellow puzzlers in the meantime, please let us know in the comments!

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Sudoku Around the World!

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Sudoku is the most popular pen-and-paper puzzle since the crossword. No other puzzles come close. Whether it’s in your local paper, our iPad app, or one of the magazines offered by our friends at Penny/Dell Puzzles, chances are you’ve solved a Sudoku puzzle at one time or another.

And the solving experience is an integral part of its success. When you look at a Sudoku grid, you instinctively know what sort of puzzle you’re dealing with and what the goal is. You don’t need the instructions or any elaborate explanations. You can simply dive right in.

That sort of simplicity and accessibility gives Sudoku major appeal, and has contributed to its success as an iconic puzzle worldwide.

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Look at this stack of puzzle books from around the world, loaned to me by a friend of the blog!

There are Sudoku books in Russian, French, Japanese, and other languages! And yet, you could pick up any one of these magazines and start solving immediately.

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Here are two Samurai Sudoku from a Russian puzzle magazine. Again, these are identical to the overlapping grids you find in the States.

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I did, however, encounter a few intriguing variations I was unfamiliar with as I perused these magazines published by 777.

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Instead of providing sums in smaller boxes within the grid like Sum-Doku puzzles, or along the edges like Kakuro, these puzzles offer totals that correspond to the three diagonal boxes in a line a given arrow points to.

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In this Sudoku variant, there are no repeats of the numbers 1 through 8 in a given row or column, but there are also no repeats within each group of connected circles.

Again, although I couldn’t read the instructions for these new puzzles, I was easily able to figure out the mechanics of each and start solving within a few minutes. Very few puzzles have that sort of universal accessibility.

sudokuworld9

While I’m very familiar with Kakuro (or Cross Sums) puzzles, I’ve never encountered cut-style grids like these. I just love the simple elegance of these diamond-shaped grids. Very eye-catching.

Believe it or not, this is just a sampling of the hundreds and hundreds of Sudoku magazines and puzzle books released over the last decade.

Although the puzzle as we know it has been around since the ’70s under other names (To the Nines and Number Place, among them), it was only relatively recently that it exploded in popularity, becoming a true cultural touchstone and undeniable puzzle phenomenon.

[For another blog post exploring puzzle books from around the world, click here!]

Thanks for visiting PuzzleNation Blog today! You can share your pictures with us on Instagram, friend us on Facebook, check us out on Twitter, Pinterest, and Tumblr, and be sure to check out the growing library of PuzzleNation apps and games!

The Wide World of Sudoku

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hypersudokufromsudokusolverdotnet

[A classic Sudoku grid with a colorful twist, where the 3×3 blue squares also have all 9 numbers inside them. One of many MANY Sudoku variants. Grid from Sudoku-Solver.net]

For more than a century now, crosswords have been the premier pencil-and-paper (or pen-and-paper, if you’re confident) puzzle, but a close second would have to be Sudoku, which has exploded in popularity over the last decade or so.

The simple concept behind Sudoku — a 9×9 grid arranged so that the numbers 1 through 9 only appear once in each row, column, and 3×3 square — is easily modified for any difficulty level, from beginners to topnotch solvers.

The classic form of Sudoku, originally known as Number Place or To the Nines, is instantly recognizable.

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[A Sudoku grid from PuzzleNation’s own free Classic Sudoku app for iPad.]

But virtually any set of nine different symbols, characters, numbers, or letters can be used as clues for a Sudoku-style solve. That gives us variations like Picture Sudoku or Color Sudoku, where the same deduction is involved, but the solution is a bit more vibrant.

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[A color Sudoku from Aleph.se.]

Word Sudoku follows the same concept, replacing the numbers 1 through 9 with letters, allowing for the added bonus of a 9-letter word reading out along one of the rows. I’ve seen Word Sudoku variations in all sorts of languages, which is neat, because you can still solve the puzzle even if you don’t know the language; you’re simply choosing different symbols.

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[A Word Sudoku from Magic Word Square on Blogspot.]

Using letters instead of numbers often factors into larger Sudoku puzzles. While Penny/Dell’s Mega Sudoku is a 16×16 grid using the numbers 1 through 16, other large-scale Sudoku puzzles use letters instead of numbers above 10, while others go so far as to remove the numbers altogether, giving you the option of puzzles that span nearly the entire alphabet!

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[A 25×25 monster Sudoku grid using letters, courtesy of colinj.co.uk]

And since we’re already discussing bigger Sudoku puzzles, it’s worth mentioning smaller Sudoku puzzles. Often called Mini-Sudoku or Sub-Doku, these puzzles start at 4×4 grids (using only the numbers 1 through 4) and increase in size all the way up to the standard 9×9 grid.

Those are just the puzzles that use standard Sudoku rules. There are numerous types of Sudoku that add new rules or curious wrinkles to the standard solve.

Perhaps the most famous variant is known as Extreme Sudoku, Diagonal Sudoku, or X-Sudoku, and there’s one crucial difference: the numbers 1 through 9 also appear only once along each diagonal. This additional rule helps with solving, but Extreme Sudoku puzzles often have fewer set numbers in order to keep the difficulty level interesting.

extremesudoku

Another popular variation is known as Jigsaw Sudoku or Geometric Sudoku. These puzzles abandon the standard 3×3 boxes, instead using various Tetris-like shapes within the 9×9 grid. Each of these pieces contains each number 1 through 9, and the standard rule of no repeats within a row or a column remains.

These puzzles can either have random shapes or shapes with the same diagonal symmetry that rules both crossword grids and the placement of set numbers in classic Sudoku grids.

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[A Jigsaw Sudoku grid from AnyPuzzle.com]

Some variations involve more deduction as well, like Neighbor Order Sudoku or Greater Than Sudoku. These puzzles feature small arrows that indicate whether the number in a given square is larger or smaller than its neighbor.

That’s just the start of math-based Sudoku variants that exist. Sum-Doku or Killer Sudoku uses the standard one-per-row, column, and 3×3 box Sudoku rule, but also adds numerous smaller Tetris shapes and boxes, each with a total. The numbers within that smaller box add up to that total.

Those totals are a crucial aid for solving, since Sum-doku puzzles often feature many fewer starting numbers. (The shapes of the smaller boxes often follow the diagonal symmetry of the set numbers.)

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[A Sum-Doku grid from Crossword.Nalench.com]

Another popular variant involves overlapping Sudoku grids. You could have two 9×9 grids that share one 3×3 box, or two 9×9 grids sharing four 3×3 boxes, or you could have more grids overlapping in all sorts of ways.

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[A quadruple overlapping Sudoku grid, courtesy of the forums of enjoysudoku.com]

The best known overlapping Sudoku puzzle is probably Samurai Sudoku, which features five 9×9 grids, one at the center and one at each corner, so the 4 corner 3×3 boxes of the center grid link the puzzle together.

Check out this masterpiece I discovered on mathpuzzle.com:

5-way-hybridsudokufrommathpuzzledotcom

Not only is it a Samurai Sudoku with diagonal symmetry for all the set numbers, but each of the four corner grids operates under a different set of variant rules.

The upper left grid uses Extreme Sudoku (or Diagonal Sudoku) rules, the upper right grid is an asymmetric Jigsaw Sudoku (or Geometric Sudoku), the lower left grid has shaded the location of every even-numbered number to aid your solving, and the bottom right has two shaded ribbons weaving throughout the grid, each of which also includes each number from 1 through 9 once.

As you might expect, there are plenty of variations of Samurai Sudoku. My personal favorite is known as Shogun Sudoku; it’s two linked Samurai Sudoku grids — meaning there are ELEVEN linked 9×9 grids — and there are even larger variations out there for the solver who simply can’t get enough of overlapping Sudoku puzzles.

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[Upper left: Tight Fit Sudoku, Upper Right: Thermo Sudoku,
Lower Left: Arrow Sudoku, Lower Right: Consecutive Sudoku.]

Our friends at Penny/Dell Puzzles have several titles that offer a variety of different Sudoku puzzles. The four grids above all appear in various issues of Will Shortz’s WordPlay, all courtesy of Sudoku constructor Thomas Snyder.

You should also check out the Sudoku Spectacular title (featured in our Holiday Puzzly Gift Guide!) as well as their upcoming Will Shortz’s Sudoku title.

I would also be remiss if I didn’t mention the mathier cousins of Sudoku.

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Kakuro, also known as Cross Sums, follows the same no-repeats rule of classic Sudoku, but the grids are much closer to Crosswords. The numbers along the top and left-side are the total for each row or column, and they are the primary clues for solving the puzzle. Kakuro rarely features set numbers the way Sudoku does, instead opting for a single filled-in row or column to get the solver started.

kenkenfromthemathmagazineonblogspot

[A 6×6 KenKen grid, courtesy of The Math Magazine on Blogspot]

KenKen takes the addition from Sum-Doku and adds subtraction, multiplication, and division to the mix. Each box has a number and a mathematical symbol. The number is the total, and the symbol is how the missing numbers interact to reach that total. For instance, in the upper right corner of the grid, there’s 24X. That means the two missing numbers from that box, when multiplied, equal 24.

And since this is a 6×6 grid, following the same one-per-row and column rules of Sudoku, you know that 4 and 6 are the missing numbers in that box, but you don’t necessarily know where to place them yet.

When it comes to Sudoku, the variations on shapes and layouts are seemingly endless. I’ve seen diamonds and snowflakes, cubes and five-pointed stars, in all sorts of sizes. You can get Samurai Sudoku with 6×6 grids, Jigsaw Sudoku in miniature, and Word Sudoku with Egyptian hieroglyphics.

While researching this post, I encountered this marvelous Sudoku variant, which the constructor calls Star Sudoku.

starsudoku1

The numbers 1 through 9 appear once in each triangle, and there are no repeats along any row or slanted column. This puzzle is not only clever, it’s flat-out neat.

So, fellow puzzlers, what’s your favorite variation of Sudoku? Or do you prefer to stick with the classic version? Let me know! I’d love to hear from you!

Thanks for visiting PuzzleNation Blog today! You can share your pictures with us on Instagram, friend us on Facebook, check us out on Twitter, Pinterest, and Tumblr, and be sure to check out the growing library of PuzzleNation apps and games!

PuzzleNation How-to: Sudoku!

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Sudoku is one of the most popular paper puzzles in the history of puzzling, perhaps the only puzzle to rival crosswords in the hearts of solvers worldwide.

That being said, I frequently encounter people who have either never tried to solve Sudoku puzzles or had a dismal first showing that dissuaded them from trying again. And today, I’d like to reach out to the Sudoku disenfranchised out there with a PuzzleNation How-To.

How to solve Sudoku, to be specific!

[Brief historical tidbit: The Sudoku puzzle as we know it was created in 1979 for Dell Magazines by puzzler Howard Garns (though it was introduced under the name Number Place). Before its rebranding in the modern era, it was also known as To the Nines.]

The rules of Sudoku seem simple enough. It’s the solver’s job to place the numbers 1 through 9 in every row, column, and 3×3 square in a 9×9 grid.

[Additional brief historical tidbit: Each row and column add up to 45, making every Sudoku puzzle a variation on the classic Magic Square puzzle concept. Only Extreme Sudoku puzzles — puzzles where the numbers 1 through 9 also appear along the diagonals — qualify as true Magic Squares, grids where the sum of every row, column, and diagonal all add up to the same number. Magic Squares have been around for more than 2000 years, giving Sudoku an impressive puzzly pedigree.]

Sudoku puzzles come in all sorts of sizes and difficulty rankings — most of which are dependent on where numbers are set, how many are set, and what numbers are set — and the placement of set numbers often adheres to the same diagonal symmetry as black squares in crosswords.

Let’s look at a sample puzzle, shall we?

The best way to start a Sudoku puzzle is to scan for numbers that appear most frequently, since they’ll offer more hints pointing toward where to place other numbers.

For instance, we’ve got a 7 in the top left-hand 3×3 grid (on the top row) and a 7 in the top center grid (in the middle row), so let’s try placing a 7 in the top right-hand grid.

Since a number can only appear once in each row, column, and 3×3 grid, we can draw imaginary lines crossing out the open spaces in the top row, the middle row, and the rightmost column, leaving only one space remaining where the 7 could possibly go.

Let’s continue with 7s and see if we can place a 7 in the middle left-hand grid.

Between the 7s in the top row, the middle row, and the second column from the left, there’s only one open space for that 7.

With this new 7 in place, we can also determine the 7 in the bottom left-hand grid.

Our new 7 eliminates any spots in the leftmost column, and the given 7s in the second column and the middle row eliminate all possibilities but one.

With this new information, we can place the last 7 in the bottom right-hand grid.

Focusing on one number can deliver a lot of new information early on.

Now, after filling in a few more numbers, we can move into more of the deduction aspects of Sudoku solving.

Look at the middle grid on the left-hand side. There are only two numbers missing from this 3×3 square, the 5 and the 8. While we don’t have enough information to place them, this box can help us place numbers in the top and bottom left-hand squares.

The second column has four numbers missing — the 1, the 2, the 5, and the 8 — and we know the 5 and the 8 will be in that middle grid.

This means that there are only two options for the 1 and the 2, the top left-hand space and the bottom left-hand space.

And since there’s already a 1 in the top left-hand square and a 2 in the bottom left-hand square, it’s easy to place our numbers.

That sort of deduction can be extremely helpful when it comes to harder Sudoku puzzles. Here’s another example, a little farther into our solve.

In this case, we’re going to try to place a 3 in the center 3×3 square. We know from the placement of other 3s in the grid that the 3 cannot be in the bottom row or the middle row.

Unfortunately, we don’t know which of the open boxes in the top row will hold our 3.

But, thanks to this information, we can place the 3 in the middle grid on the right-hand side. Here’s the grid with the 3s we know for certain.

Since we know the center square’s 3 will occupy one of two places in that top row, we can also eliminate that row from the possibilities for the middle grid on the right-hand side.

We can now place the 3 in the remaining square, and move forward with our solve.

From this point onward, you’ll be able to fill the entire grid with ease, adding the first of many vanquished Sudoku puzzles to your solving experience.

I hope you found this PuzzleNation How-to helpful. All of the graphics came from our Classic Sudoku app, now available for the iPad!

(Although the black lines were for illustrative purposes only, you can place possible numbers in blue just as I did with our Candidates feature.)

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