When you toenail a board, it tends to move over away from its designated mark, whether your toe is in place to stop it or not.
Try putting your board on it's mark.
Place a prybar on the other side of the board as shown in the photo and give it a good whack.
The second photo shows how the ears will bite into the wood.
Now hold the bar down in those grooves and drive your screw.
The board will stay right on it's mark.