Puzzle #205: SOS

Consider a tic-tac-toe grid. Instead of three X’s or O’s, how many ways can you put SOS in a horizontal, vertical, or diagonal row?

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, May 10, 2017 at noon Pacific Time. I will post the answer shortly after.