With reference to enlisting for military service during the U.S. war with North Viet Nam; "The first Vietnam draft lottery was held on December 1, 1969, at Selective Service National Headquarters in Washington, D.C.. The lottery determined the order of call for induction during 1970 for men born between January 1, 1944, and December 31, 1950. The lottery was the first time a lottery system had been used to select men for military service in the US since 1942.
The second lottery drawing took place on July 1, 1969 and was for men born in the year, 1951. I lucked out, big-time, when I learned my number was 303. ....
One's draft lottery number could be any number from one to 365, and for this July 1, 1970 lottery, it was reported that any number above 180 was considered very unlikely to get drafted.