Strength, weight and aggressiveness are as essential to a good guard as speed is to an end. A slow, lumbering guard is of no use; in fact, a slow man has no place in the game. Upon the center and the two guards depends the strength of the line and the strength here must be that of a stone wall, in order that the various offensive plays may be gotten well under way before the opponents can get through to break them up. The work that falls upon the guard calls for great exertion and instant action. The area of his play is limited, but if his position is attacked he must go through on the instant, as plays at that point in the line strike immediately.

When playing on the offensive, the guard must line up quickly, not more than a foot from his center - practically shoulder to shoulder. He should stand facing the opposing guard, ready to block him the instant the ball is put into play. He must never allow himself to be drawn out, for then the opposing center or defensive quarter back can break through. The guard should also play very low, as he cannot open holes in the line or do successful blocking when playing high.

After he has opened the hole, the guard can often help the runner by pulling him along or by pushing him from behind, especially if the attack is on his side of the center. When the attack is on the center's opposite side, the guard should go through between the opposing guard and center, and block out the guard. Then, when he is through and behind the opposing line, he can cut off the opposing half tack, part of the enemy's reinforcements, and, crossing over the center line, may possibly pull the runner along or interfere for him.

The guard is almost useless as a ground gainer, if used from his position. He may be called back behind the line, however, and used in the same way as a tackle, either for interference or for carrying the ball.

On defense the guard should play close to center, crouching low, facing the front, as this will be the direction from which the strong attack will come. The guard must not be drawn out too wide, although he is responsible for the hole between himself and tackle. He should be very effective in helping the center to stop all plays aimed at his position. He must never be caught "up in the air," for mass plays must be stopped from the bottom. The guard should always go through straight ahead, carrying the opposing guard back into the play or forcing him toward center, while he himself goes through instantly on the outside. He should go through on every play and never back off his own line. He should not wait and use his discretion about going through the line, for the attack of the opponents is too varied. Consequently, many of the plays seemingly meant for the opposite side of the line - and actually started in that direction - really strike at the position of the often-deceived guard.

When his side is kicking, the guard should play close to center and block long and effectively. He is practically in front of the kicker and, if he permits anyone to get through his position, the opponent will be directly in front of the kicker and will probably block his kick or interfere with the distance or the direction of the punt.

At the kick-off, after the kick, a guard should go down directly under the ball to prevent any return and to be on hand to line up instantly when the ball is downed. When the opponents are kicking, the guard is in one of the best positions to block kicks or to aid in getting the center or the other guard through for that purpose. The three center men should work together to get one of their number through. They can easily arrange a signal which will indicate what each one is to do and which one is to go through. With mutual assistance thus secured, one of the trio should go through almost instantly, as the defensive men have the free use of the hands and arms and so should be able to jerk open the opposing line. To illustrate, if the signal called for the center to go through, the left guard should pull his man to the left and the right guard can jerk the opposing center over to the right. At the same instant the center can assist by pushing the right guard to the left, with the left hand, using his right to open up the hole still further by pushing the opposing center further out of the way. This should open a road for the center to the punter. The man who goes through, if he does not block the kick, should hurry the punter so that he cannot get good distance or direction.

A guard should play upon the line of scrimmage, study his man, learn his methods and never be caught twice in the same way. Many of the methods of penetrating the opposing line will come to the guard who studies the situation. Too many players are machine-like in their methods. They are not versatile. They do not use their brains. The chief lesson for the football player to learn is the necessity for headwork.