← Iris
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Door 1
Door 2
Door 3
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Switch win %
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Stay win %
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Win rate comparison
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Auto-play
Why switching works: When you first pick, you have a 1/3 chance of being right. The host always reveals a goat, which gives you no new information about your door — but it concentrates the remaining 2/3 probability onto the one unopened door you didn’t pick. Switching is equivalent to betting you were wrong initially — and you were wrong 2/3 of the time.