The fallacy of Backward Probability Calculation

Picture of Heath Ledger playing as the Joker character in The Dark Knight (2008) movie. He is holding us a Joker card in his right hand.

By Eric Bright

Here is a simple puzzle for you with deep implications.

I have a deck of Bicycle cards with 52 cards plus two 🃏 Jokers (a black and white and a coloured one), as well as one Bicycle 🚲 introduction card, and an advertising card (56 cards in total).

I have been shuffling them for the past two months or so. Today, I got the following sequence of cards:

K♥, 5♠, 6♦, 5♥, 8♠, 7♦, K♣, 8♣, A♠, 4♥, 2♥, J♥, 8♦, 🃏C, 3♠, Q♦, 🃏B&W, A♥, 5♦, A♦, 9♠, Q♣, 2♣, 10♣, 3♦, K♠, J♦, 7♥, 🚲-ad., 9♦, 7♣, A♣, 3♥, J♣, 8♥, 4♣, 3♣, 4♦, 2♠, 10♠, 🚲-intro, Q♠, 9♣, 6♣, 10♥, 7♠, J♠, 4♠, 6♠, 5♣, 6♥, 10♦, 9♥, Q♥, K♦, 2♦. read more...

Please cite this article as: Bright, Eric. (2018) The fallacy of Backward Probability Calculation. BlogSophy. https://sophy.ca/blog/2018/12/the-fallacy-of-backward-probability-calculation/