Draft Number

In the United States’ conflict in Vietnam, the government decided to draft (conscript) certain young men into military service. An attempt was made to ensure that each eligible man would have the same probability of being chosen (random sampling): each of the 366 days of the year was assigned a draft number (Jan 1=1 to Dec 31=366), and each number was written on a piece of paper, spun in a drum, and pulled out; the order of the numbers pulled out was the order in which eligible men with those birthdays were drafted. It has been alleged that insufficient mixing caused the process to be biased so that those with birthdays later in the year were on average drafted much earlier than those with early birthdays.