So, the site wants me to do this:
board[guess_row][guess_col] = "X"
But that changes the wrong element, because the lists are indexed 0:4, not 1:5. And it won't allow the user to even guess 5! So the correct code would be:
board[guess_row-1][guess_col-1] = "X"
The other solution for this is to make guesses = raw input -1. I guess that is more permanent too though. might try that.