The position of half back is one that is hard to fill. The half backs, together with the full back, are expected to be the standard ground gainers of the eleven. The half back is called upon to make fierce plunges into the line and rapid dashes around the end. Hence great care should be used in the selection of men to fill the half back positions. They should be chosen for speed, grit and endurance. Each should have a quick eye and the ability to act on the instant as the situation demands. The hole in the opposing line will not always be where it is expected and the interference will not always be as desired. The half back should use his eyes constantly, to take advantage of any opening or hurdle anyone who may fall under the interference, thereby becoming a "dead one."
It should be decided at the very first which half back position the candidate is to fill, for, while the general duties of the two half backs are practically the same, the plays are in opposite directions. The position for the half back to assume on the defensive depends on the style of game that the team is playing. There is little left of the old formation of three backs in a row. Several of the latest formations and the positions of the half backs in these are shown in the chapter on "Offense." All of the back field men should exercise great care in taking the same positions of foot, body, hand and eye in all the formations. They should not, by word or by act, give away the point of attack or the direction in which the play is going. This is very important, yet many good backs are guilty of such offenses.
In bucking the line, the half back should go in low and hard. This does not mean that he should carry his head so low that he cannot see where he is going; the body must be carried low without having the head bent down. If the back does not use his eyes he is just as likely to run into one of his own men or into the arms of an opponent as into the opening. In line smashing, the back should carry the ball against the pit of the stomach. He should hold it securely with both arms, for he need not use either hand to ward off interference, as this would be useless in straight line smashing. He should by all means keep his feet, so that his team mates can help him along, and he must not be thrown toward his own goal; he and his helpers must prevent this. On all plays around the end or just outside of tackle the half back should carry the ball under his outside arm; he will then have the other arm free to keep off the opposing tacklers. Very few half backs make use of this important feature of their work. No back should ever run toward his own goal; his duty is to gain ground, not to lose that already made.
Carrying the ball is not more than one-third of the work required of a half back on the offensive. The half back must work just as hard and conscientiously when the other men on the team have the ball. He is then required to go into the interference and "clear the track" of opposing tack-lers, or to aid in pushing or pulling the runner along for an extra yard on plunges through the line.
The defensive work of the half back depends largely upon the style of attack used by the opponents, but all back-field men should, if possible, be able to kick, be sure tack-lers and be proficient in the handling of punts. The directions in these features of his game are given elsewhere under their respective heads.