Gap control is a key component to a good defense. Every defender in the nucleus of the defense (defensive linemen and linebackers) is responsible for a gap between two offensive blockers. For example, assume that the defensive lineman is poised at the line of scrimmage, ready for the offense to run a play. At the snap of the ball, the offensive lineman initiates a run block (either a reach block or a cutoff block), trying to take over the defensive lineman’s gap. The defensive lineman must be able to read the block, determine that the play is a run and keep control of his gap. He has to keep his gap-side arm free without giving up too much ground laterally. If a defensive lineman loses control of his gap, either by being reached (when he is a playside defender) or by being cut off (when he is a backside defender), a seam opens up and the ball carrier will be able to run through to the safeties.
The following circumstances may distract your athletes:
• The quarterback’s cadence. The snap of the ball, not the sounds being made, keys the movement of the defensive line.
• Focusing on backfield action after the snap. Defenders must read and defend the block before they find the ball.
• Peeking into another gap and trying to make a play. Staying gap sound is crucial. If the ball goes to a teammate’s gap, the defender must trust that his teammate will make the play.
When controlling the gap, you and your athletes should understand the following:
You and your athletes need to know several main rules when controlling the gap:
• Trying to get a jump on the snap will usually result in an offside penalty. Defenders must key the ball and react, not guess when the ball will be snapped.
• Offensive linemen aren’t permitted to hold, but they will. Defenders must knock the blockers hands away and realize that the officials will not often call the hold.
The physical playing conditions significantly affect the game. Thus, you and your players must pay attention to the following physical conditions when controlling the gap:
• Wet or slippery field conditions might cause the defender to slip on his important first reaction step. He must narrow his stance and take shorter, quicker, more controlled steps to avoid slipping.
You and your players must account for your opponent’s strengths and weaknesses to know how to control the gap properly. Consider the following about your opponents:
• How quick are the offensive linemen? A quick offensive lineman is more likely to beat the defensive lineman on a reach or cutoff block than a slower offensive lineman is. Against the quicker blocker, the defender should take a looser shade, lining up a little bit wider to make the reach and cutoff blocks more difficult. Against a slower blocker, the defender can play a tighter shade.
• Are the offensive linemen vulnerable to an inside move? Through scouting or experimentation early in the game, the defense should assess whether the offensive linemen can handle slant moves by the defensive line. The threat of an inside move can cause the offensive lineman to be less aggressive on his reach block. (The defense has to be sure, however, that the linebackers adjust to defend the gap vacated by the slanting defensive lineman.)
Besides being aware of your opponent’s strengths and weaknesses, you and your players need to know about your own team’s ability. Teach your players to be aware of the following when controlling the gap:
• How tight a shade can the defensive lineman play? A defensive lineman’s first rule is: Don’t get reached. The looser the shade he plays, the less likely it is that he will be reached. If he plays too loose a shade, however, the offensive blocker will have a clear release to block up on a linebacker or back on another defender. The defensive lineman must learn to play the tightest possible shade that he can without being reached. That way, he can collide with the offensive blocker when the blocker is not trying to reach him, and he can stay gap sound when the blocker attempts the reach block.
• How well do your defensive linemen read offensive blocking schemes, and how quickly do they react? Through drills in practice and studying tapes of games, you must evaluate and train your defensive linemen on their ability to read and react. The better the defensive linemen do this, the more often and effectively the defense can play a base defensive scheme without having to use line games and stunts. If the defensive line is inconsistent at reading and reacting, the defense may have to rely on line games and stunts, which can be effective but carry a high risk of allowing a big play.
• How physical and aggressive are the defensive linemen? A tough, physical, aggressive defensive lineman can make up for a slow read or a bad first step by tenaciously battling the offensive blocker throughout the play. This type of defender might initially appear to have been reached or cut off, but he might be able to fight back, counter the block and regain proper leverage.
When deciding how to gain the best advantage when controlling the gap, you and your players should consider the previous information as well as the following guidelines:
• If the offensive lineman’s initial steps threaten the defender’s gap, the defender must counter that attack by moving his feet in that direction while repositioning his hands to the gap-side shoulder of the blocker.
• After neutralizing the blocker, the defender must see the path of the ball carrier and determine whether the ball is coming at him or going outside. If the ball carrier is threatening his gap, the defensive lineman must use aggressive hand action to shed the blocker and make a tackle. If the ball is going outside, he can focus on moving laterally in that direction, running away from his blocker and pursuing the play.
• The defender must be sure not to open the door to the next gap inside! He has to keep his outside arm free and his head outside, but if he gives up too much ground laterally to keep his outside position, the next gap inside will get larger and larger, making it difficult for the defender assigned to that gap to do his job. Defenders must fight the pressure of the reach block and give ground grudgingly while maintaining appropriate leverage.
This is an excerpt from Coaching Football Technical and Tactical Skills.