Pennsylvania – Landscaping – Energy – Environment
Chinook helicopter preparing to lift a disabled Huey from a Vietnam War firebase in late-1971.
Lottery Numbers by Birth Date for Selective Service Lottery held on July 1, 1970. This lottery determined the order in which men born in 1951 were called to report for induction into the military.
Lottery Numbers by Birth Date for Selective Service Lottery held on August 5, 1971. This lottery determined the order in which men born in 1952 were called to report for induction into the military.
Lottery Numbers by Birth Date for Selective Service Lottery held on February 2, 1972. (The draft ended on July 1, 1973). This lottery determined the order in which men born in 1953 were called to report for induction into the military.
Email from Gerry L:
As someone whose life was determined by that first draft in 1969, there is a missing story (today). It wasn’t actually a “random drawing.”
Oh, it looked like one. But if you went back (as some statisticians did much later) and looked at the outcome and then the process, you can clearly see a fundamental flaw.
Future drafts had two rotating barrels, one with birth dates and one with numbers. Those were, in fact, random.
But the 1969 draft had just one container, with birthdates, and the “number” was determined by when the date was pulled out, with the first date pulled getting #1, and so on.
But then they made a fundamental error. The dates were entered in that one barrel not randomly, but with December on the bottom up to January on the top. When it came time to do the drawing, the barrel was inverted and shaken a bit. That was enough to “sort of” disperse the dates, but not anywhere near enough to make them truly randomly distributed.
What happened then was the late summer/fall birthdays were more likely to be near the top and the winter/spring birthdays nearer the bottom. And low and behold, statistically it was proven later that fall birthdays had a whoppingly higher chance of being drawn in the first third of the draft, and it was those 1-120 numbers that ended up being called. (In my case, called in 1972. I realize the call went higher between 1969 and 1972)
This statistical anomaly was brought to you by November birthday #034, with a June birthday college roommate who got the ultimate: #366 (the first draft included leap years).
Turns out you don’t need to be a statistician to see the prevalence of lower numbers in the fall and not in the winter/spring.
Here are the frequency of draft numbers 1 to 120 in the initial 1969 Vietnam-era draft.
In a perfectly random world, they should be about 10 per month, recognizing the months are not all equal in length and some variation will always occur.
Jan – 8
Feb – 7
Mar – 3
Q1 – 18
Apr – 8
May – 8
Jun – 11
Q2 – 27
Jul – 10
Aug – 13
Sep – 8
Q3 – 31
Oct – 9
Nov – 11
Dec – 16
Q4 – 36
The Q4 (fall) birthdays saw double the rate of the Q1 (winter) birthdays! That is statistically nearly impossible, unless the methodology was flawed, as it was.
Hope you find this interesting, and perhaps even worthy of inclusion on your site.
More: 1969 Draft Lottery
Vietnam War & Draft Lottery index