Pick a door!

Behind one door is a car. The other two have goats. Click a door to choose!

Wins: 0Losses: 0Switched: 0Stayed: 0

Monty Hall Problem

Experience the famous Monty Hall probability puzzle interactively. Pick one of three doors, watch the host reveal a goat, and decide whether to switch or stay. The game tracks your wins, losses, and switch/stay ratio so you can see the counter-intuitive 2/3 probability advantage of switching play out over time.


Frequently Asked Questions

What is the Monty Hall problem?
The Monty Hall problem is a famous probability puzzle based on the TV game show 'Let's Make a Deal.' You pick one of three doors. The host, who knows what's behind each door, opens another door to reveal a goat. You then choose whether to stick with your original pick or switch to the remaining door. Statistically, switching gives you a 2/3 chance of winning the car.
Should I switch or stay?
You should switch! When you first pick a door, you have a 1/3 chance of picking the car. The host always reveals a goat, so switching gives you a 2/3 chance of winning. Play many rounds and check your stats to see this probability in action.
Why does switching work?
When you first choose, there's a 1/3 chance your door has the car and a 2/3 chance the car is behind one of the other two doors. When the host reveals a goat behind one of those two doors, the entire 2/3 probability transfers to the remaining unopened door. So switching doubles your odds.
Is the Monty Hall simulation fair?
Yes! The car is placed randomly behind one of the three doors using a uniform random generator. The host always reveals a door with a goat that you didn't pick, exactly like the original problem.
Does the game track my statistics?
Yes, the game tracks your total wins, losses, how many times you switched vs. stayed, and your overall win rate. Stats are saved in your browser so they persist between visits.