Edward Thorp is a mathematician who did a lot of analysis about blackjack over 50 years ago.[1] He's a seminal figure in this field.
Here's one site I recall mostly because it has a memorable name: http://wizardofodds.com/
[1] https://en.wikipedia.org/wiki/Beat_the_Dealer#History
It's obviously not common knowledge to the person that's asking the question. :~) Thanks for the source though.
That said, the edge is not always below 1%. It varies based on the rules. Some games don't allow a surrender, for instance, which changes the edge pretty drastically.
