The Drunkard's Keith

The Drunkard's Walk: How Randomness Rules our Lives, by Leonard Mlodinow.  Every once in a while I like to mix things up and read some non-fiction, mostly about interesting phenomena and how they influence our lives.  I've read all of Malcolm Gladwell's recent work, also Freakonomics and Predictably Irrational, all of which I highly recommend.  The Drunkard's Walk is another such book, and Mlodinow explains how purely random things can happen to change our lives everyday.  He explains wine reviews, bell curves in grading, the lottery and the stock market in the view of pure randomness.

Mlodinow gives many examples and anecdotes from his own life to illustrate the points he is making, although it is clear that it is a brilliantly gifted scientist and mathematician speaking and not an author.  Some of the stuff can be very difficult to follow and it gets very in depth.  Mlodinow also spends a lot of time speaking about the history of the study of chance, focusing on many different individuals from the 17th, 18th and 19th centuries in Europe.  I thought there was too much history and not enough real world applications at times.

However, one thing I will take away from this book is this fascinating mathematical riddle: Suppose you are on a game show, and you are shown three doors.  The host explains that behind one door is a grand prize, and behind the other two are nothing.  He asks you to make a selection.  You pick Door #1, let's say.  The host then opens Door #3, revealing that it contains nothing.  The host then gives you a second chance to change your answer.  Should you stick with Door #1, or change your answer to Door #2?  Now for many people, including myself at first, the answer seemed obvious.  There would be no difference between the doors, there is a 50-50 chance either way, so there is no mathematical advantage in switching.  Wrong.

When you first made the selection of Door #1, there was a 33% chance you guessed correctly.  There was a 66% chance you guessed incorrectly.  When the host opened Door #3 he removed it from play and manipulated the playing field.  Now, Door #1 still has that 33% chance of being correct, but Door #2 has a 66% chance of being correct, so it logically follows that you should change your answer and choose Door #2.  Unless of course, you are feeling really lucky.

Different from my normal repetoire of books, but good in it's own way.  Three out of five stars.