Out there in his home on the net, the ever sharp Bill Gates has put out a review of How Not to Be Wrong: The Power of Mathematical Thinking by Jordan Ellenberg.

The way he deals with the lottery is a great example. For several years, the Massachusetts lottery ran in a way that allowed three teams—one led by an MIT student, one by a medical researcher, and one by a guy from Michigan—to game the system and win millions of dollars. You might ask, How could the state let them cheat like that for so long? Part of the answer is, the state didn’t care. Massachusetts got 80 cents for every $2 lottery ticket sold, no matter who won. And the second part of the answer is, they weren’t cheating. They were taking advantage of math to give themselves slightly better odds at winning and other people slightly worse odds. They basically turned themselves into the house at a casino.