Football’s offensive linemen are separated by gaps, which are labelled alphabetically from the inside.
On an offensive line, there are two B gaps between the offensive guard and offensive tackle.
When targeting this area between the guard and tackle, both offenses and defenses use the B gap terminology.
It is expected that the offense will use the B gap as a running lane to carry the ball. The defense will pass rush and clog up this section of the field with their defensive line.
Clogging Up the B Gap
Football defensive linemen and linebackers are often assigned specific offensive line gaps to cover.
By running into their assigned gaps, these players will prevent the ball carrier from passing.
Defenses such as the 4-2-6 use a one-gap system, where each defender covers only one gap, while others use a two-gap system, in which defenders cover two gaps each.
The one-gap system would assign one defender to each B gap. This allows these players to play extremely aggressively, as they can rush this gap the second they recognize a rushing play is in progress.
Two-gap defenders, on the other hand, need to cover multiple gaps, such as the A and B gaps on the strong side.
In two gap situations, players must be a bit more cautious with their approach, as overcommitting to one gap can be costly. Two gap players must wait until they determine which hole the ball carrier is trying to pass through.
In this way, they can avoid filling the wrong area between offensive linemen.
Defensive tackles and linebackers will fill in the B gap in defense. Edge defenders will fill in the C gap, which is outside the offensive tackle.
Pass Rushing
Instead of just rushing at the quarterback in general, teams will attack a specific area of the field when they rush the quarterback.
In order to confuse offensive linemen, defensive players often switch gaps or overload gaps.
A team may line up several players on top of the C gap prior to the snap. Once the play begins, several players move in another direction and one rushes that gap.
In this situation, offensive players may have difficulty identifying who to block.
The defensive tackles usually rush the B gap on regular pass-rushing downs.
A one-on-one matchup may occur in the B gap, but the center may also assist from time to time.
Rushing the Ball
In football, the offense will also use the B gap by carrying the ball through it.
In offensive rushing plays, the ball carrier will always target a predetermined gap.
This gap will be known to all offensive players, who will look to move defenders away from it.
The tackle and guard will play an extremely significant role when running the ball through the B gap.
Keeping the defensive tackle from getting between the guard and the offensive tackle will be the guard’s responsibility.
It is the offensive tackle’s responsibility to block the edge defender who is pushing him towards the outside. If executed correctly, these blocks should leave a hole for the ball carrier to travel through.
It is also common for the offense to send the lead blockers through the gap first on some rushing plays, usually the fullbacks.
The player will go through the hole first and block the linebackers or defensive backs waiting on the other side.