1Two things to notice first
Your guess is 1-in-3, and the host's hint is loaded
You only need these two ideas. Watch each one:
Your first pick is a 1-in-3 guess
Three doors, one prize. When you pick blind, you're right only 1 time in 3. So 2 times in 3, the prize is behind a door you DIDN'T pick.
The host already knows
The host isn't guessing. He knows where the prize is, and he always opens a losing door — never the prize. That hint is loaded, not random.
2Two ways to play
Stay on your door, or switch to the other one
After the host opens a losing door, two closed doors are left: yours, and one other. You get one choice:
Stay
Stick with the very first door you picked. Don't move.
Switch
Jump to the other closed door — the one you didn't pick and the host didn't open.
3Your turn — play a round
Pick a door, watch the host, then decide
Tap a door to pick it. The host will open a losing door for you. Then choose stay or switch and see if you win. Play as many rounds as you like.
Tap a door to pick it 👇
4Now run it hundreds of times
One round can fool you. Hundreds can't. 🎯
A single round is luck. To really see which plan is better, you have to play a LOT of rounds the same way and count. Guess first — then let it rip.
Guess before you run it
You picked door 1. The host opens door 3 (a loser) and offers you a switch to door 2. Over hundreds of rounds, which plan wins more often?