Author interviews Vol.17 Ryohei Nakai

Around the AuthorsInterviewsAuthor round-tableOne Layout AkarisOne Layout Slitherlinks

Talking to Ryohei Nakai

Ryohei Nakai is a 23 year old graduate student. He seems to have studied optimization deeply. He is a computer programmer able to turn anything into code.

NyanBazWhat kind of kid were you when you were little?

Ryohei NakaiIn elementary school I played football and baseball. And I was playing with a computer named MSX2 doing BASIC programming.

NyanBazYou were interested in computer programming even in those days. When did you start on puzzles?

Ryohei NakaiThat was in 2nd or 3rd year of elementary school. In the Sunday edition of our newspaper, there was a regular puzzle that turned into a picture when it was solved. At first, my parents were doing it, I imitated them, and I was able to finish solving it. After that, I bought magazines with similar puzzles and played at those.

NyanBazWhen did you get to know Nikoli?

Ryohei NakaiIn the puzzle magazine I just told about, there was a puzzle with rules that looked like Slitherlink. I looked for that in the bookstore, and there I found a Nikoli book that I bought, one of the pencil puzzle book series with Slitherlink. I tried it out, but to me at that time it seemed to be difficult, I could not solve much. Frustrated, I ended up copying the whole answer. I probably threw that book away. I got tired of it and for a while I stayed away from puzzles.

NyanBazHow'd you know. Then, when did you return to puzzles?

Ryohei NakaiIt was the winter in the second grade of junior high school. I have an elder brother who is about ten years older. He gave me a present "Puzzle Communication Nikoli." Interesting, he said. I think it was Vol. 89. That time I conquered almost all that was in it. I had a good time. I especially liked Slitherlink & Heyawake. Ever since then I started to buy "Puzzle Communication Nikoli".

NyanBazYou have a great brother. And incidently, this brother of yours is a puzzle author too.

Ryohei NakaiYes. He and I live apart now, so I feel good when I see his problems somewhere. And I go "oh." Knowing he is doing fine, is great.

NyanBazGood to hear that. In the latest issue "Puzzle Communication Nikoli" Vol. 124 there is a lot of work by your brother, more than work by you. Do you you feel sorry about that?

Ryohei NakaiNo, I don't feel anything like that. I don't think that I want to improve on that especially. I just think that he has managed his time better. (laughs)

NyanBazWhen did you start making puzzles?

Ryohei NakaiThere was a "how to make Slitherlink" section in "Puzzle Communication Nikoli" Vol. 90, I began to make puzzles after reading that. I think it was in the third grade of junior high school. I made mainly Slitherlink, but my first published work was Dainarizumu (It's a figure puzzle in "Puzzle Communication Nikoli" at that time).

NyanBazThen you kept it up ever since?

Ryohei NakaiI got a little tired of it when I was in first year of college. My interest in this goes up and down.

NyanBazIs that how you go about it. Did you ever think it good that you have continued with puzzles?

Ryohei NakaiI get more acquaintances that way. In college I was one of the organizers of the school festival circle, and we got to talking about puzzles. There was another person who liked puzzle there besides me. It was really happy. I have often participated in time trial competitions to solve puzzles, then, there I became friendly with someone who is not an author, just solves puzzles. And of course, thanks to puzzles I get to participate in interviews like now.

NyanBazDo you still like Slitherlink?

Ryohei NakaiYes I like Slitherlink. And besides Slitherlink, I like other puzzles that make loops, like Masyu and Yajilin. When there are several lines to connect, following them as they wiggle their way around is a great feeling. For solving I like difficult LITS. aspirin's puzzles, that kind of thing. I try to imitate that but it won't turn out right.

NyanBazAre there puzzles you don't really like?

Ryohei NakaiFor making puzzles, I'm not good at Sudoku. Anyway I do, they seem to go wrong. I think that Kakuro is a difficult puzzle to make too. It is difficult for me to arrange the black cells. I still have a long way to go though I'm researching other authors' works. Sometimes I have trouble solving problems I have made myself. If others have to solve such problems, it may be even more difficult for them. I don't want to publish that kind of problems.

NyanBazYou're good at making easy problems?

Ryohei NakaiThat's right. I like to make easy problems whether I am good at it or not. I want to make problems that seem pleasant when solving them. And, easy problems are good, being completed in a short time. That is why I want to make many problems like that.

NyanBazI think there are different kinds of pleasant. What is pleasant for you?

Ryohei NakaiProbably, flow. I think that to have a natural flow to carry things along makes it feel pleasant. I think that in an easy problem it is easy to express a natural flow. Therefore, I'm making mainly easy problems. Of course, also hard problems, but with understandable tactical moves, if they seem natural, they could be pleasant problems too.

NyanBazFor yourself, the flow of the problem, do you think it up when you are making it, or is the thinking done before making the problem?

Ryohei NakaiI'm almost always deciding things before I put it down on paper. At first I make a solution scenario, I make an actual problem so that everyone can solve it as in the scenario. Therefore, I don't make many large sized problems. Large sized problems have to have a lot of entrance points. Then, the problem can be solved from various starting points. Therefore, I don't feel that I control the flow as easily as I would wish. However, if I had better technique, it is likely I'd be able to make that flow like I wish too.

NyanBazThere are a lot of authors who want to make strange problems or problems with flashes of surprise. Don't you want to make such problems?

Ryohei NakaiHmm, other authors are doing that, so I don't have to. I am aiming at the standard, I'm happy enough with that. But I also sometimes do make a weird problem. (laughs)

NyanBazWhen and where do you make your puzzles?

Ryohei NakaiAt night, in my room. I cherish the natural flow, so I have to have a quiet environment to get it right. I rarely make puzzles where it is not quiet, for example in trains. I'm occasionally solving puzzles on the trains. The puzzles that I solve on trains are only Sudoku and Kakuro. These 2 kinds of puzzles are fun even if you only do them a little at a time.

NyanBazRight, Sudoku and Kakuro can be solved without looking at the whole grid.

Ryohei NakaiThe other extreme, the full overall picture becomes important for Slitherlink. Therefore, Slitherlink isn't good for solving and making on trains I think. And drawing lines on the train, just thinking about it makes me feel bad. (laughs)

NyanBazYou said it. (laughs) Then, you always make puzzles in longhand?

Ryohei NakaiYes. I'm writing in notebooks like this. (Taking a notebook out of his bag. )

NyanBazLet me see? Oh, beautiful! But this is not a fair copy just notes, isn't it?

Ryohei NakaiSure. I make almost all my puzzles in notebooks like this.

NyanBazI make puzzles in freehand too, but it becomes messy with notes to myself and modifications in the work. But this beauty is wonderful!

Ryohei NakaiWell? Maybe it's because I'm blood type A. (laughs)

NyanBazThen are there things that you cannot get across when you make your puzzles?

Ryohei NakaiI don't know whether this is an answer, but basically I start from the top left. When the puzzles has solid marks or there are black cells like in Nurikabe, solving it from the right with a pencil the hand gets dirty. I try to consider the people who have to solve them, as far as possible.

NyanBazYou sure think about it all. How many puzzles have you made so far?

Ryohei NakaiWell, I don't really know. I have never really counted them.

NyanBazThen, is there a masterpiece among them?

Ryohei NakaiNo, there is nothing like that. If there were a masterpiece, I think it would be the end for me. I've placed my goal out beyond the reach of anything.

NyanBazWhat is your ideal puzzle?

Ryohei NakaiIt would be a puzzle where everybody says it is fun. I don't know which one that would be though. But, I am sure I'd try to make it without fail. I am going to make puzzles groping for the very best.

NyanBazWonderful! A last question, what is your message to the solvers who have enjoyed your puzzles.

Ryohei NakaiJust enjoy yourself and keep solving. I'm sure you are up to it. Relax and have a fun time.


Interviewed Sep 2008 Published on Jun 29, 2010