Everyone loves the El Farol Bar in Santa Fe, New Mexico (especially W. Brian Arthur, who wrote this puzzle in 1994).

That is, everyone loves the El Farol as long as it's not too crowded.

If it's less than 60% full, it's more fun to be at the bar; if it's more than 60% full, it's more fun to stay home. This puzzle has one more catch: everyone has to decide whether or not to
go at exactly the same time, without communication.

So what should you do—stay home or go to the bar?

You can probably see the Catch 22 here.

So rather than asking if you should stay home or go to the bar, a more precise question is what's your best strategy? Does the number of total people in the deciding pool compared to the carrying capacity of the bar make a difference? Would history affect your strategy? If you were allowed to communicate, what should you tell people about your choice?

I'll post the answer tomorrow morning.

Here's a little experiment. First close your right eye and look at the picture of my new book (at left). And now close your left eye and look at the picture of beer on the right. Now as quickly as you can, blink to alternate your eyes between the two pictures. Do you feel inexplicably drawn to buying Brain Candy?