Geez, my handwriting didn’t look that bad before I had my coffee this morning!

Although you can run any kind of play out of this formation, it’s primarily used in the run game.  As the quarterback hands off to the tailback, the fullback acts as a blocker; the advantage of the I formation is that the tailback has a better view of the overall defense. Because he’s set back from the line of scrimmage by about five to seven yards, the tailback can see the entire defensive line and react to any changes they might make as the play commences.