So I'm a statistician, right? A general fan of science and facts and stuff. A stickler for evidence. The kind of person whose mantra is correlation does not necessarily imply causation, except when the causal relationship in question isn't based on quantitative data and therefore can't really be described using the term "correlation," in which case the dubious argument is better criticized by referencing the logical fallacy "post hoc ergo propter hoc." (Because I'm also the kind of person who is a pain-in-the-ass stickler for using the word "correlation" correctly.)
So, it follows that I wouldn't be into any sort of mystical divination practices, since their fakeness is fairly obvious. Even my homegirl Hermione rolls her eyes at them. She trusts the judgment of a telepathic singing hat, but not someone's subjective interpretation of a pile of tea leaves, because even literal witches know that divination is bullshit.
That is my embarrassing hobby: I read tarot cards. I don't believe they have any predictive power, but I know how to do the spreads and interpret them as though they do. The only excuses I have for why I read tarot cards are
- You can convince drunk people that you're magic
- They're pretty
- It's kind of like Rorschach blots, you know? The meaning that you impose on the ambiguity can highlight thoughts, feelings, and motivations that might otherwise be difficult to identify
- They're really pretty
- Did I mention how pretty they are
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| they are really very pretty |
So I blew it off and shuffled again, because Lauren is awesome and deserves a fortune-telling session that predicts piles of cash and hookers (lookin' at you, ten of pentacles). And the new cards were a reversed high priestess (impatience, wasted potential), a five of pentacles (poverty and bad luck), and the goddamned devil (which is pretty much as bad as it sounds).
This ridiculous bullshit continued for about seven more drawings, separated by increasingly intense shuffling sessions, including the foolproof throw-all-the-cards-in-the-air-and-swear-loudly method. Time and again, Lauren got cards that weren't just irrelevant or neutral, but seemed to be actively shitting on her dreams. More than once, she shouted at me, "you're a statistician-- what are the odds of this?"
Challenge accepted!
At first I thought it would be pretty easy to answer Lauren's question. How many ways can there be to draw three cards from a deck? While a card's position in its spread usually affects its interpretation, we weren't applying any past-present-future or problem-advice-outcome meanings to the three card spreads we were doing, so order doesn't matter for our purposes. There's 78 cards in a tarot deck, so there's 76,076 possible hands of three.
Now we just have to determine how many of those spreads would be unfavorable for Lauren's education! This part turned out to be trickier.
Since orientation affects interpretation, each of the 78 cards has 2 possible outcomes, for 156 total. I categorized each of these 156 outcomes as positive, negative, or irrelevant with regard to Lauren's education, because ambiguity is for chumps. Of those, there are 43 good possibilities (28%), 64 bad possibilities (41%), and 49 possibilities (31%) that have no bearing on Lauren's question (get outta here two of cups, we weren't asking about crushes). I defined an unfavorable spread as any combination of three cards that includes no positive results and at least one negative result: either all negatives, two negatives and an irrelevant, or one negative and two irrelevant.
And that's where I ran into a bit of a problem. See, I planned to calculate all the different ways one could draw any of those three hands using plain old n-choose-k, where I'd be looking for how many ways to choose 3 negative cards from the pool of 64... but there aren't exactly 64 negative cards. It's impossible for me to first draw an upright eight of swords (feeling trapped by circumstance) and then draw a reversed eight of swords (feeling trapped by circumstance, but like, even worse). But I've included both the upright and reversed versions of the card in my tally of negative outcomes. Essentially, I've backed myself into a mathematical corner where I've artificially doubled the size of the deck: I'm doing calculations based on 156 outcomes, rather than 78 outcomes with two variations each.
To be truly rigorous, I should tally up how many cards switch from positive to negative, from irrelevant to positive, from negative to irrelevant, etc, versus how many cards maintain their general meaning when reversed, and work those numbers into much longer calculations of conditional probability.
Yeah, I based my calculations on the imaginary 156-card deck, where each orientation of each card counts as its own separate card. It's fortune-telling, for crying out loud, I'm not going to worry too much about rigor.
If we allow the fudge-factor of a theoretical 156-card deck to deal with the problem of card orientation, there are 620,620 possible combinations of three cards that one can draw from a tarot deck. There are 41,664 ways to get three negative cards, 98,784 ways to get two negative cards and one irrelevant card, and 75,264 ways to get two irrelevant cards and one negative card.
All together, that's 215,712 crappy hands, out of 620,620 possible hands. There's about a 35% chance that any individual tarot reading I do for Lauren's educational prospects will be negative. If we multiply things out to reflect the fact that Lauren got eight successive crappy readings, we get a probability of just over 0.02%. So... huh. Dang Lauren, sure looks like the universe has it in for you.
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| Technically, the universe has it in for all of us. Enjoy your inevitable disintegration, everything! <3 Entropy |
