April 29, 2009

Ask the Geek: Deal or No Deal

Q. Can you help me win on that Deal or No Deal show?

A. Yes, if winning means maximizing the amount of money you take home, not picking the right suitcases.

Here is my advice: 

Forget about winning the million dollars. The odds say it just won’t happen. The object of the game should be to beat the mysterious Banker, not win the million dollars. To do that, you need to think in terms of expected value.

It makes no difference which suitcase you pick. Each has the same probability of having any one particular number in it. As a contestant, then, you should add up all the dollar amounts on the board at any time and divide by the number of choices left…or in other words, take the average.

The Banker is doing the same thing – figuring out the expected value (or in this case, the average) of all the choices left and then coming up with a number that is higher or lower than that value. If the number he offers to pay you is higher than the expected value (or average) of all the numbers you computed on the board, then you should take his offer. If not, keep playing.

Most people on the show are playing the wrong game – trying to win the million dollars. It’s not going to happen. Beating the Banker is the best you can do.

Try to figure out those expected values the next time you’re watching. You might be surprised how quickly you get the hang of it.

E-mail me if you have a question.

Cale

Posted by Cale at 8:31 AM in Ask the Geek

Tags: ,

Post a Comment

Recently on Twitter...

$TNDM This is the comp the mkt worries about? Peerless can't seem to raise VC $, more discounts & use credit lines...? http://bit.ly/bQo0Fd 2 days ago

this blog
Riffs, rants and the upside of investing from way off Wall Street.
About Cale

I'm a portfolio manager at Islamorada Investment Management in the Florida Keys. Email me at caleinthekeys@gmail.com.

islamorada
An amazing place. Read An Ode to Islamorada.
Quotable

Scholars have long known that fishing eventually turns men into philosophers. Unfortunately, it is almost impossible to buy decent tackle on a philosopher’s salary. — Patrick McManus