A recent thread on X by @iamluismalheiro has reignited interest in a fascinating problem. In his thread, Luis recounts the 1990 controversy sparked by Marilyn vos Savant, who famously tackled the puzzle in her “Ask Marilyn” column. Before we get to the controversy, let's play the game. Ready? There are three doors. Behind one is a car—a gleaming, shiny, make-your-friends-jealous car. The other two? Goats. What happens to the goats if you win is anyone’s guess, but let’s stay focused.
Pick a door. 1, 2, or 3. Got one? Great. Let’s say you picked door 1. Now, the host opens door 3 to reveal…a goat. Now comes the big moment. The host gives you a choice: stick with your original pick, or switch to door 2?
What do you do?
If you switched, congrats—you just won a brand new 1965 Pontiac Tempest! If you didn’t, well…enjoy your new goat.
But why? Why does switching lead to victory twice as often as staying with the original door?
The puzzle that stumped millions
This is the Monty Hall Problem, named after the host of the classic game show
Let’s Make a Deal. It’s simple enough to explain, but the math behind it has baffled people for decades. Even PhDs and mathematicians have gotten it wrong.
The question boils down to this: When Monty opens the door to reveal a goat, does switching increase your odds of winning the car?
The answer is yes—switching doubles your chances of winning.
Marilyn’s bold answer—and the backlash
In 1990, Marilyn vos Savant, recognized for having one of the highest recorded IQs, confidently declared, “Yes, you should switch.” Her answer was based on solid math, but it provoked a storm of criticism. She received over 10,000 letters, including nearly 1,000 from PhDs. Many accused her of misunderstanding the problem or even being incapable of basic logic. Others resorted to personal attacks:
"You are the goat!"
— Anonymous critic
Some critiques veered into outright sexism:
"Maybe women look at math problems differently than men."
— Anonymous critic
But Marilyn stood her ground, unwavering in her confidence. Over time, her answer was proven right by computer simulations run by MIT, as well as by experiments conducted by
MythBusters. Eventually, many academics who had criticized her publicly apologized for their errors, acknowledging her insight and logic. The ordeal transformed Marilyn into a symbol of intellectual resilience, and her calm persistence in the face of hostility continues to inspire people today.
Marilyn’s lasting legacy
Marilyn often reflected on her experience, noting how the backlash revealed deeper issues with how we approach learning and problem-solving. She attributed much of the confusion—and the vitriol—to flaws in the education system. “Our schools teach us to memorize answers, not to question them,” she argued, advocating for an approach to education that encourages independent thinking.
Despite the loneliness that sometimes accompanied her intellect, Marilyn saw her gift as a blessing. “It’s not easy being this smart,” she admitted, but she never shied away from using her platform to challenge conventional thinking. Her Monty Hall response remains one of the most famous examples of sticking to the truth in the face of overwhelming opposition.
Today, her story is a reminder that being right doesn’t always mean being popular—but it’s worth standing firm. As Luis Malheiro’s viral thread shows, the Monty Hall Problem continues to fascinate people, thanks in no small part to Marilyn’s courage and conviction.
Here’s the math
Let’s break it down. When you first choose a door, you have a 1/3 chance of picking the car and a 2/3 chance of picking a goat. If you’ve picked a goat (which happens 2/3 of the time), switching after the host reveals another goat guarantees the car.
It's a numbers game backed up by MIT supercomputers and the Mythbusters alike:
- Pick the car (1/3 chance): Switching loses.
- Pick a goat (2/3 chance): Switching wins.
So, by switching, you win 2/3 of the time.
"Switching wins 2/3 of the time."
— Luis Malheiro
Why is it so hard to grasp?
The Monty Hall Problem messes with our intuition. Most people reset the odds after the host reveals a goat, assuming it’s now a 50/50 choice between the remaining doors. But the math doesn’t work that way—the odds of your initial pick being correct stay at 1/3.
In her defense of the solution, Marilyn criticized the education system for fostering
passive learners who lack the tools to think critically. It’s a critique that feels just as relevant today.
The thread blowing up on X
Luis Malheiro’s
thread has reignited the debate, drawing millions of views and sparking conversations about math, intuition, and education. Many users shared their disbelief at the backlash Marilyn endured, while others admitted they’d initially gotten the problem wrong themselves.
"It’s not easy being this smart."
— Marilyn vos Savant
Why it matters
The Monty Hall Problem isn’t just a fun game show puzzle—it’s a reminder of the importance of critical thinking and the courage to stand by the truth, even when it’s unpopular. Threads like Luis’s help bring these lessons to a new audience.
So, the next time you’re faced with a tough choice, consider the Monty Hall Problem. Sometimes, the smartest move is to switch.