All you people saying it increases your odds 17%, to 50% are wrong according to my computer simulation and vos savant herself.
[You must be logged in to view images. Log in or Register.]
Those who swap always get the opposite of their original choice, so those who swap have 2/3 chance of winning the car (Carlton 2005).
The outcome is fairly obvious from the 1 line of code
Code:
return (switch_doors) ? !doors[choice] : doors[choice];
If you switch, you invert your choice. You had a 2/3 chance of being wrong the first time (1/3 chance of winning)