In an Xbox world, Howard Rachelson remains defiantly low-tech. His idea of a good time is revving up the ol’ gray matter and putting it through its paces in a friendly game of trivia.

As founder of the Mayflower Inn Trivia Night in San Rafael, it’s safe to say Rachelson is a walking encyclopedia. A math teacher at the Jewish Community High School of the Bay, Rachelson not only kept the Mayflower game going strong for 20 years, he also has created and hosted many Jewish community trivia events across the Bay Area.

In fact, the Mayflower Inn Trivia Night is about to celebrate its 20th anniversary Thursday, Oct. 28.

He’s the best friend useless information ever had.

Rachelson is something of a Renaissance man. He has traveled to 50 countries and taught mathematics in Switzerland, England and Israel, as well as here in the Bay Area. He also plays the piano and recently published a book, “Trivia Café,” which includes more than 2,000 questions on topics ranging from animals and food to world history.

He first got interested in trivia-as-sport back in the early 1980s while teaching at the American International School in Herzliya, Israel. He had attended a social event featuring a fast-paced team-oriented trivia game.

“Every table was a team,” he recalls. “It was so exciting, the next year I helped run the show. Then at the school I did a quiz bowl on general knowledge and Jewish knowledge.”

Rachelson and his family returned to the United States in 1983. His wife, Evi, became active with B’nai B’rith Women. It wasn’t long before she volunteered him to host a trivia night/fund-raiser for the organization, and he soon became a highly sought-after quizmaster at other Jewish events. He also hosted quiz bowls at the Branson School, where he was a teacher.

But the big kahuna of Rachelson trivia events has been the weekly Mayflower Inn event. For 20 years, week in and week out, he has composed a slate of questions, including a few audio and visual stumpers, for the packed house of minutiae mavens.

Has anyone ever cheated?

“The most egregious act of cheating,” remembers Rachelson, “was when someone called a library in Honolulu because the local one had already closed.”

And just to add to his mitzvah account, Rachelson also runs a regular trivia contest for seniors at Rhoda Goldman Plaza in San Francisco. “They love it,” he says. “It keeps their minds alert.”

The San Rafael resident is a member of Congregation Rodef Sholom, where his wife works as an early childhood educator. They have two grown children, which leaves Rachelson plenty of time to peruse his library of trivia references and surf the Web for more extraneous facts.

“People are intelligent by nature,” says Rachelson. “They’ve gone to college, they read books and magazines, they know facts and have opinions. Trivia contests give people a chance to use the knowledge they’ve accumulated over the years.”

Mayflower Inn Trivia Night 20th anniversary bash takes place 7:30 p.m. Thursday, Oct. 28, at the Mayflower Inn, 1533 Fourth St., San Rafael. Entry fee $3 in advance, $5 at door. Information: (415) 456-1011.