How did we get the two car tandems at Daytona and Talladea in the first place?

The Races last year at Daytona and Talladega showed what we crave for, three wide racing and exciting finishes as well as a crash or two, basically pack racing. How did the two car draft even spring into it? What changed at Daytona and how did it affect Talladega this year as well, i am so confused? I miss that racing and would love to see it back. Does anyone know how the two car draft came to be?