re: Can somebody explain to me the 1972 Season?

It's pretty simple. The SEC title didn't mean that much back then. It wasn't tied to the Sugar Bowl, and there were no serious rewards for it. Auburn happened to play 7 conference games that year, while Bama played 8, but several teams only played 6.

For several years Auburn also played one less game due to its academic schedule (quarters). Auburn had its serious rivalry with Tech, which Bama had dropped. So several factors, all simple, explain why Auburn played one less conference game than some other teams.