Outside the Ball asked two American stars, CoCo Vandeweghe and Steve Johnson, to weigh in on the great American burger debate: Five Guys vs. In-N-Out.

Both Johnson and Vandeweghe are Californians, so their answer was expected, In-N-Out. Vandeweghe listed four strong reasons for her choice: grilled onions, secret menu, options and milkshakes. Even their orders were the same—double-double cheeseburger, fries and a milkshake.

"We're California people," Johnson said. "We just know."