As regards the duties of the place, they differ from those of any other position in the line on account of the constant presence at that spot of the ball. The centre is either playing the ball himself or watching his antagonist play the ball at every down; so that while he has all the other duties of a forward to execute, he has the special work besides. Here is the weakness of so many centres. They are snap-backs only or forwards only, the former being by all odds the more common. A good critical coach of experience will see nine out of every ten men whom he may watch in this position playing through day after day with no more idea of doing any forward work than if they were referees. Putting the ball in play at the right time, and properly, is a great achievement, but it does not free the centre-rush from all other obligations. He must protect his quarter; he must aid in making openings, and perform any interference that may be possible, as well as always assisting a runner of his own side with weight or protection. He must always get down the field under a kick, for it is by no means unusual for him to have the best opportunity in these days when end rushers are so carefully watched. When the opponents have the ball, he must not be content with seeing that the opponent does not roll it to a guard, but must also see that there is no short, tricky passing in the scrimmage. Then he must be as ready as either guard to meet, stop, or turn a wedge. He must make openings for his comrades to get through, even when he himself may be blocked, and always be ready to reach out or throw himself before a coming runner to check the advance. [Illustration: JESSE RIGGS. Princeton.]