LITTLE COULD Google have known, when it recently hired an expert author of crosswords, that the company would need not one custom puzzle to feature on its home page by today. Rather dramatically — and in a dash to deadline — it would require two.

At the 11th hour, the first planned crossword had to be shut DOWN. Fortunately, Google’s veteran crossword guru, working swiftly so close to the finish line, was coolly able to get a new, second puzzle ACROSS.

And it’s that second interactive creation — built and retooled with hours to spare — that is featured much of this weekend as Google’s home-page “Doodle,” which celebrates the 100th anniversary of the crossword’s birth.

View Photo Gallery: Here’s a look at other Google Doodles.

.On Dec. 21, 1913, British-born newspaper editor Arthur Wynne — looking to spice up a Christmas issue — published the world’s first crossword puzzle in the New York World. As crossword constructor Merl Reagle recently wrote in The Washington Post, recounting Wynne’s “Eureka!” moment: “He drew a diamond-shaped grid with numbered squares and numbered clues. It contained 32 words, and his simple instruction read: ‘Fill in the small squares with words which agree with the following definitions.’ ”

Wynne’s crossword was a quick hit with the brain-teased masses.

So when Reagle was hired this fall to freelance for Google, he decided to write a custom crossword that saluted the puzzle’s inventor — including nods to Wynne’s name in the answers, as well as to his diamond-shaped grid.

Just one problem: In the world of crossword authorship, sometimes great minds — these men and women of letters — think alike. (When, say, a fittingly named Diana Nyad makes headlines for her record swim, these clue masters can be quick to jump in the same mythology-versed pool.).

So it was late last week when the minds behind the new Crossword Doodle — including Google engineer Tom Tabanao and Team Google Doodle artist Brian Kaas — shared an incredulous e-mail that said:

“Do you believe this?”

Turns out, noted crossword constructor Matt Gaffney had just published a similar Wynne-homage puzzle of his own to mark the anniversary.

“I spotted the Gaffney puzzle,” says Tabanao, 34. “I saw the diagonal pattern and before I even saw the answers, I had this sinking feeling. I said: ‘Are you kidding me?’ ”

The Google team soon huddled. “We had an emergency conference that afternoon,” Tabanao tells Comic Riffs. “I said: ‘Don’t panic all at once. First, you panic ... ,’ “ he jokes.

Fortunately for the Bay Area-based company, Reagle — who creates crosswords for numerous outlets, including The Post and the San Francisco Chronicle — is a level-headed veteran of brain-game authorship. (He sold his first crossword to the New York Times about a half-century ago — at age 16.) He can write a crossword in a matter of hours. So he decided to take his Wynne tribute a level or two deeper.

“I cranked out a new puzzle — a more ‘fun’ puzzle — with a better angle,” says Reagle — his own quote containing a clue as to his new approach.

Reagle is known as an especially clever clue-creator, employing jokes and other sly wordplay in his puzzles. (”My style of puzzle is … populist and gag-oriented,” says Reagle, who tosses off a one-liner about a socially awkward duck being “mallard-justed.”)

In this case, for his new Google crossword, Reagle knew that Wynne once edited a newspaper section titled Fun. So — what’s a three-letter word for “spoiler alert”? — Reagle laced today’s large crossword with words that (both forward and backward) contain the word “fun.” (Hint: Think both “perfunctory” and “snuff.”)

For a Google Doodle, Reagle says, the puzzle “can’t be overly brainy and can’t be overly gimmicky. It’s got to be something right down the middle of the plate.”

For Tabanao — a self-described “hard-core” puzzler who has solved Reagle’s puzzles in the Chronicle for some time — the Doodle is the culmination of a joyful collaboration.

Kaas, 38, pitched the idea of a crossword Doodle last summer, but the proposal lost out to higher-priority projects. It was Tabanao who, on his own time and of his own initiative, worked on coding a puzzle prototype and got the idea off the ground.

One challenge Tabanao and Kaas tackled was how to present the puzzle — with its scores of clues — so Google visitors would be readily engaged. That meant creating a puzzle that expanded to fill much of the screen. “As much as possible, your Google home page will be taken over by this puzzle,” Kaas says. “We wanted to give you the full sense — let you get this gestalt image.”

“We wanted to make it so the most people can see it and view it,” Tabanao says. “We tried to make it possible to enjoy it and play with…across browsers.”

The Crossword Doodle is save-able as you go, the team notes, so you can leave the screen and return. The puzzle — as well as a player’s completion time — is also shareable via social media.

Google doesn’t plan to provide an answer key — instead counting on the passion of fans to share their answers on YouTube and elsewhere.

Yet perhaps the puzzle-builder’s best answer isn’t even in this Doodle. Asked about why the crossword endures with unflagging popularity a century later, Reagle says: “Whether you’re getting coffee or going to work ... it’s the idea of getting a daily fix.”


[THE POST: 100th anniversary Crossword Puzzle Contest]