Since I am editing my personal statement, I went to the bookshelf with all my parents' old books to see if there was anything on grammar. I noticed this real old (1962) book on proper grammar. Since that's from when grammar mattered, I figured I'd take a look.
One of the sections was on superfluous commas. In the sample sentence below, I'm going to write first how I would write that sentence and then how they say to.
1.) Under the circumstances, I should have been wearing a coat.
2.) Under the circumstances I should have been wearing a coat.
The second way gets rid of "superfluous commas," but it's not my style. Would either way be fine, or is the second way definitely correct.