WASHINGTON — The news might have set off alarms in some past administrations: The president’s brother-in-law has written a book.

But you won’t find dirty laundry in a memoir from first ladyMichelle Obama’sbrother, Oregon State basketball coachCraig Robinson. The book, “”A Game of Character,”” which has a foreword by their mother,Marian Robinson, is due out on April 20.

Craig Robinsonwrites that he and his parents didn’t thinkBarack Obamastood much of a chance with his sister when they met him.

He and his parents were out on their porch on a hot summer night in Chicago when the couple stopped by to say hello on their way to a movie.

“”Well, he’s tall,””Marian Robinsonsaid while Obama was out of earshot.

“”Not a bad-looking guy either,”” said her husband, Fraser.

But even though the suitor struck the Robinsons as a self-possessed man with a nice smile and firm handshake, they figured he wasn’t a keeper. “”Too bad,”” Marian said. “”Yep,”” Fraser answered. “”She’ll eat him alive.””

Craig Robinson, 47, less than two years older than Michelle, was close to his only sibling. In childhood, they even shared a bedroom separated by a divider.

Miche, as he calls her, was a disciplined, scholarly girl who saved money fastidiously, who learned to box at their father’s behest and who once conspired with him, upset that their parents smoked, to destroy every last cigarette in the house.

In the book,Fraser Robinsonis dubbed “”Philosopher in Chief”” in the forward, and his long struggle with multiple sclerosis is treated with much compassion by his son. The father died in 1991 at age 56.

Craig Robinsonwrites that both parents urged him to excel and quotes his mother as saying: “”Knowledge acquired is something no one can take away from you.””

He also says Obama sought his help in convincing Michelle and Marian that he should give the presidential race a go. His sister, he said, was reluctant for another campaign so soon after he was elected to the Senate.

After Obama became president, Michelle turned to her brother to encourageMarian Robinsonto move into the White House, Robinson writes in her forward.

“”As a compromise, I opted to move to the White House after all, at least temporarily — while still reserving lots of time to travel and to maintain a certain amount of autonomy.””

The book is sprinkled with life lessons on how this brother and sister excelled and howCraig Robinson, when confronted with challenge — including a rocky academic start at Princeton University and a first marriage that ended in divorce — picked himself up.

But amid homespun stories of the family’s humble roots and Robinson’s climb to a college-level coaching career (after a foray into the world of finance), people hungering for more aboutBarack and Michelle Obamamay be a bit disappointed.

Robinson writes mostly about basketball, even when describing how he introduced his sister before her prime-time address at the Democratic National Convention.

“”Michelle was being asked to sink a three-pointer at the buzzer in a do-or-die game at the start of the championship,”” he writes. “”Everything to come, victory or disappointment, would hinge on this one shot. And all I could do to help was simply pass her the ball. And believe.””