”Astronomical.” What are the odds that two good books about Jeopardy! would be published simultaneously?

Can’t resist beginning this review in the standard Jeopardy! format, answer before question. The bigger name here is Ken Jennings, with his unprecedented 74-game, $2.5 million winning streak in 2004, and his Brainiac hooks you with its charming self-deprecation. But don’t ignore Bob Harris, five-time Jeopardy! winner, whose Prisoner of Trebekistan is a surprisingly touching memoir.

Despite strikingly different backgrounds, Jennings and Harris share a passion for trivia that surpasseth all understanding. Jennings, a software programmer and Mormon family man in Seattle, acquired status as a ”temporary Z-list celebrity” and ”nerd folk icon” but also a wearying nervousness about ”the whole charade” of keeping his initial run of wins a secret until they actually aired.

Like Harris, Jennings is gratifyingly forthcoming on buzzer technique, the most mystifying detail for home viewers. You know how sometimes you see a contestant frantically pumping his or her buzzer over and over, while the go-ahead light flashes on another’s podium? These guys not only explain precisely when you must ”ring in,” but detail their hours of practice with homemade buzzers.

Each book has its own trivia-detail pleasures, as when Jennings reveals he learned mythology from Thor comics and loves British director Michael Powell’s films. But sometimes Jennings’ chapters on the history of trivia are tedious. (Sorry, I just don’t care that Thomas Edison subjected all his job applicants to a 150-question trivia test.)

Brainiac offers a mother lode of tips on strategy if you so much as daydream about trying out for the show (as does Trebekistan). Both men come off as decent and generous. And so, again in Jeopardy! form: ”An honest grade.” What is B+?