Hypergeometric Probabilities

Codex
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I was inspired earlier due to a discussion of people wanting to have a table that enumerates the probabilities of drawing the card you need while at a physical tournament. I ended up making something you could probably find a use for in PbF as well.

Here you go!

Card Draw Probability Spreadsheet

Feel free to discuss or point out errors.

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Row 4 column 3
{75.0%, 50.0%}

What does it mean ?
Drawing 3 cards from 4 card deck result in 50% chance of drawing your card if you have 2 copies of it ? 75% if you have just one?

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That’s great, thanks !

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Fixed.

The second number used to be showing the probability to draw exactly 1, without adding the probability for drawing exactly 2. So now the second number shows 1 or more when there are 2 copies in your deck, and the first number shows the probability to draw exactly 1, because there is only 1 in your deck.

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Nice, it makes sense now.

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Neat! Thanks for making this

A couple suggestions that might make it easier to read:

  • Take out the { } in each cell. It adds a bit of visual clutter that makes it harder to quickly scan the numbers
  • Maybe add a color gradient with conditional formatting from high to low probabilities? Might be hard to do if there are two numbers. I suppose you could split the table for 1 card vs. 2 card, but it’s useful to have both numbers in case you are considering how many copies of something to tech in order to get a card after reshuffle.
  • Color coding the 1 vs. 2 card case would make it easier to scan, although I don’t know how to do that without tedious manual formatting. You’d probably need to have separate columns for each number
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I like your suggestions, I think it would be doable. I could implement a color gradient, but i think that wil just tell you what you already know, the probability gets much better as you move to the right, and worse as you move down.

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I think for visual-oriented folks, the color gradient would be useful, even if you already know it.

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question: the table at the end, you cannot modify the numbers. is it intended?

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If you want to modify, use the Google sheets copy sheet function, under the file menu to make a local copy for yourself and you will be able to modify it then.

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I changed it so the shared sheet can be modified in those specific 4 cells for the formula, though note that does mean anyone can see what you are doing if you are looking at it at the same time.

So for a real game, I still recommend copying the sheet to your personal google sheets.

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