An interview with Will Shortz, whose KenKen puzzle books are published by St. Martin’s
PW: Where did KenKen come from, and what’s its appeal?
WS: It was invented by Tetsuya Miyamoto, a Japanese educator who runs a school in Japan. His philosophy of education is that you don’t teach kids; you provide the tools for the kids to learn themselves, and if the tools you provide are so engaging and so good the kids will want to learn. One of the methods he invented for the school was KenKen. Kids love it and, if I’m any in-dication, so do adults. It has a lot of the appeal of sudoku; it appeals to people with logical minds and in some ways it’s a richer puzzle than sudoku. It also involves numbers; in KenKen you actually use arithmetic. Kids start with the basic puzzles, which use just addition, then they move on to subtraction and all four arithmetic operations. There are different sizes and lev-els of difficulty to the puzzles; you keep advancing, you want to keep advancing and trying harder puzzles. According to Mi-yamoto, kids are solving KenKen in place of watching TV and video games.
PW: How did you discover these puzzles?
WS: A little over a year ago a toy and game agent who represents the Japanese puzzle—and who lives just a few miles from me—called and said he had something he’d like to show me. He brought it over and explained it to me; I tried one and thought, This is interesting, let me try another. And after I tried a couple I asked him to leave the book [of puzzles] with me, and I went right through it for the next week—out of 105 puzzles I solved 103. I really got addicted. Two of them stumped me at the time, but I’ll go back to them eventually—a challenge that’s still waiting.
PW: Can you compare sudoku and KenKen—is one easier than the other?
WS: Ease is not part of it. Both sudoku and KenKen can have very easy examples and very challenging ones. And that’s one of the beauties of both puzzles: they can be geared for any solving level, and for any amount of time you want the solver to spend on them. They’re both puzzles that involve wit; they both come from Japan and have Japanese names. They’re both pure logic puzzles and they both involve numbers. That’s what they have in common; the differences are that, with sudoku, the numbers act only as symbols, you don’t actually use arithmetic; whereas with KenKen you do. There’s another big difference: sudoku can be explained in a single sentence, which is a wonderful thing for a puzzle. KenKen requires maybe three sentences; that may not seem like much, but it’s a hurdle to get people over.
PW: Why have people turned from crosswords to puzzles like sudoku and KenKen?
WS: I really don’t think sudoku is taking much from away crosswords; the two have a largely different audience. Crossword people want their knowledge and vocabulary tested; crosswords reach out into the world and test you about your knowledge of every-thing. With sudoku you don’t have to know anything; it’s a pure logic game. During the [sudoku] craze those books were far outselling crosswords, my understanding now from St. Martin’s is that crosswords again have the upper hand. With all three—crosswords, sudoku and KenKen—you focus your mind on the challenge, you take it through from start to finish and feel tremendous satisfaction when you finish. And there are very few challenges where we get that satisfaction, because we rarely achieve perfection in everyday life. Puzzles like this make you feel like you’re in control of your life, if only for a short while.
PW: Why have sudoku and KenKen surfaced at this time?
WS: We never had puzzles like this the way we had puzzles before; it’s a new phenomenon. I think there a couple of reasons. Both sudoku and KenKen typically are generated by computers that have been programmed using all the logic techniques that are useful in solving them. So before the computer age these puzzles would have been difficult and time-consuming to create by hand, and probably couldn’t have been generated in large enough numbers to be successful. There’s a second reason: the world is more interconnected now, and a really successful puzzle from Japan or anywhere else can travel around the world and appear anywhere.
PW: You are the world’s only academically accredited enigmatologist. How did that come about?
WS: I’m the only person ever to do this. I went to Indiana University, which had a program called the Individualized Major Pro-gram; if you’re accepted you can major in anything you want. So I devised an entire curriculum of puzzles. However, it’s not as if, when you graduate from school, there are jobs waiting for you.