Wikipedia:Today's featured article/July 23, 2005

The Monty Hall problem is a puzzle in probability that is loosely based on the American game show Let's Make a Deal. The name comes from the show's host Monty Hall. In this puzzle a player is shown three closed doors; behind one is a car, and behind each of the other two is a goat. The player is allowed to open one door, and will win whatever is behind the door. However, after the player selects a door but before opening it, the game host opens another door revealing a goat. The host then offers the player an option to switch to the other closed door. Does switching improve the player's chance of winning the car? The answer is yes — switching results in a 2/3 chance of winning the car. The problem is also called the Monty Hall paradox, in the sense that the solution is counterintuitive, although the problem is not a logical self-contradiction.

Recently featured: Căile Ferate Române – The Ashes – Robert Heinlein