CORVALLIS — Computer programs can assemble words into a grid, but only a human can come up with a clever theme and then build a crossword puzzle around it.

CORVALLIS — Computer programs can assemble words into a grid, but only a human can come up with a clever theme and then build a crossword puzzle around it.

"Making a fresh theme that the solvers are going to like is what the editors are looking for," said Dave Sarpola, a 29-year-old cruciverbalist whose had eight of his crosswords printed in GAMES Magazine, GAMES World of Puzzles, the Los Angeles Times and the New York Times.

Crossword construction is by no means a full-time job, he said. The New York Times pays — at the most — $200 per puzzle. GAMES Magazine pays closer to $50 — a price common among other puzzle publishers.

"It takes me hours to make one, and in 21/2; years, I've had eight published, so that's not exactly a living salary," said Sarpola

By day, Sarpola is a manufacture and test engineer at Vitex, a Corvallis company that produces security products. He grew up in Corvallis, graduated from Crescent Valley High School and went on to earn a bachelor's degree in mechanical engineering from Oregon State University. He and his wife,Allison, life in Independence.

He began solving crosswords in high school and continued the hobby through adulthood. It didn't occur to him to try his hand at creating one until his friend, who had attempted to get a few crosswords published, introduced Sarpola to a crossword puzzle documentary, "Wordplay."

Sarpola's method was crude in the beginning. He used an Excel spreadsheet to build the grid and an online dictionary to help find words to fit. He printed out the finished version and mailed it to potential publishers.

Most crossword publishers these days only accept submissions by email, he learned, and the grid took about 12 hours to build.

He now uses Crossword Compiler, which formats the puzzle and allows him to right-click on spaces to show possible answers that would fit in the spot.

His first published crossword ran in the Los Angeles Times.

"It was April 26, 2011. It was a Tuesday," he said. "It was very exciting — one of the best days of my life because I had been trying for a full year to do that."

A standard crossword puzzle published in a daily newspaper follows several rules. Each puzzle is 15-by-15 squares and the grid pattern — where the black squares are placed — is symmetrical so that if the puzzle is turned upside-down, the pattern is the same.

The puzzle contains no more than 38 black squares and no more than 78 words. Two-letter words are prohibited, and all lettered squares have to be used by two words.

"Sometimes you can bend those rules, but I never do because it has to be an especially good theme for (editors) to warrant going outside those rules," Sarpola said.

The process begins with a notebook, where he lists ideas for potential themes. The longest words in the crossword usually have something in common that is not immediately obvious and is many times a play on words. For example, the longest answers in his crossword published in the New York Times this month were dungarees, garbage truck, baseball game and tackle box. What they have in common? They all contain flies.

Once he comes up with a theme, he lists as many words as possible that fit the theme. He writes them on graph paper, using one letter per square, so he can immediately see the length of the word.

Once he picks the best words that are the correct length to fit in a standard puzzle, he is ready to begin constructing the grid on his software. He begins with the theme words and tries not to work his way into a corner.

His Crossword Compiler program has an option to automatically fill the grid with words, but he considers that cheating and prefers to handpick each word. Words with rare letters such as Q, Z, K and J are preferable because they are less common. He balances choices that aren't obvious but aren't too obscure.

"It's especially good if you can get livelier, flavorful words that can have an interesting clue that solvers don't see in puzzles so often," he said, "but also that are not so obscure that it's an alternate spelling of a French word that nobody's going to know."

The clues come last. Sometimes editors will tweak crossword clues so that the level of difficulty will match the day of week it's published, Sarpola said. The Los Angeles Times publishes its easiest crosswords on Monday and they get progressively more difficult throughout the week.

Sarpola says that novice crossword puzzle solvers should start with the Monday puzzle and work their way up. There are certain things you pick up along the way, he said, like if the clue contains an abbreviation, the answer is abbreviated.

"It's a learned skill," he said. "Sometimes people will say, 'I'm not smart enough to do a crossword,' but anyone can learn to do it. It just takes time."