Hello, oldguynewstudent!

How many different outcomes are there in a best-of-nine series

between two teams A and B? Generalize to a best-of-n series where n is odd.

. . . = .the number of outcomes where wins the series.

Multiply this by two to get number of outcomes where or wins the series.

Does this look correct? . Yes!

It all looks great! . . . Nice work!