Another common mistake is to ignore improbable events. It is very unlikely that a fair coin will come up heads nineteen times in a row, so you might think it could never happen. You would be wrong. Of course, if you sat flip- ping a single coin, you might spend a very long time before you hit a se- quence of nineteen consecutive heads, but there is a way of getting this result (with a little help from your friends) in a single afternoon. You start out with $6,000 worth of pennies and put them in a large truck. (Actually, the truck need not be very large.) Dump the coins out and then pick up all the coins that come up heads. Put them back in the truck and repeat the pro- cedure nineteen times, always returning only those coins that come up heads to the truck. With tolerably good luck, on the nineteenth dump of the coins, you will get at least one coin that comes up heads again. Any such coin will have come up heads nineteen times in a row.