Hall vs. Bertrand - A lesson in EV

detroitjunkie

detroitjunkie

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Ok EV nerds, how about some mind testers. Here are two wager opportunities for you.

1. You are facing 3 boxes. In one box is $500, in the other two boxes are nothing. You get to pick one, box A, B, or C. You pick box B. I decide that I will now make you an offer. First I show you that box C is empty. Then I offer to sell you box A for $250 or allow you to keep box B but you have to pay me $200. Which do you choose?

2. You are facing 3 boxes. In each box are two drawers. Each drawer contains a coin. Box A has 1 silver coin in each drawer. Box B has 1 gold coin in each drawer. Box C has 1 gold coin in one drawer and 1 silver coin in the other drawer. I now cover up the box markings so you do not know which box is which. You get to choose one. I now allow you to reach inside one drawer of your box and you pull out a gold coin. I now offer you a bet. I bet you my $200 to your $300 that you have box B, OR I can bet you my $300 to you $200 that you have box C. Which bet do you take?

Figuring these two puzzles out will help you better understand estimated values and make you a better player overall.


DetroitJunkie
You better run squirrel
 
detroitjunkie

detroitjunkie

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maybe this belongs in the learning thread - cant believe no one even tried to answer.
 
Lucothefish

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1/ EV of box B = (1/3*500) - 200 = -$33

EV of box A = (2/3*500) -250 = +$83

2/ You're more likely to have box B, but the odds you are laying give an equal expectation on both choices.
 
detroitjunkie

detroitjunkie

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1/ EV of box B = (1/3*500) - 200 = -$33

EV of box A = (2/3*500) -250 = +$83

2/ You're more likely to have box B, but the odds you are laying give an equal expectation on both choices.

You are 3/4 correct. Got one right and half of one right
 
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