## Monday, October 18, 2010

### What’s Luck Got to Do with It? By Joseph Mazur

The book is divided into three parts – history, mathematics (probability and statistics) and the psychology of gambling.

Generally speaking this is a well written contemporary book including many interesting facts, such as the term ‘crook’ originates from the crooked dice used by gambling cheats. Another interesting section is the author’s exploration of the significance of the number 7 – the colours of a rainbow, the number of days in a week, the sum of the numbers on opposite sides of a cubical die.

Joseph Mazur gives a very tangible description of the law of large numbers, using the example of the probability of heads being approximately ½ for a large number of throws of a coin. Using the same theme the author highlights examples of the difference between the terms expected value and the mean. There is also an excellent account of the Normal Distribution.

The author gives a good description of the recent international financial crisis and reveals how closely linked Wall Street is with Las Vegas.

Mazur has made good use of illustrations, in particular when explaining possible outcomes of a game like throwing dice (Page 21).

My gripe is that sometimes numerical values are given but it is not made clear where these values have come from. For example on page 136 when referring to the lottery in New Hampshire, the book states ‘The total number of combinations of picking all six numbers is 5,245,786’. Whilst this is correct it would have been helpful to write this number as the combination formula C with superscript 42 and subscript 6 so that the reader knows that you are selecting 6 out of 42.

An issue which might cause problems for the reader is the flow of the text. The book is peppered with callouts which are mathematical justifications of particular statements. These are located at the back of the book with reference in the main text. Hence the reader is continually flicking back and forth. I think these callouts should be in the main text. You can of course choose to ignore these callouts and still understand the general concepts.

While not a serious omission I would like to have seen a callout defining standard deviation, as it is a term used throughout the mathematics section.

The book would have added substantial value if it included answers to popular statistical questions, such as: why car insurance is cheaper for women.

I only found one typo on page 121 where the Greek symbols mu and sigma are missing in the statement before the formula. Additionally this statement should follow after the formula.