With the off-season doldrums at their peak, it’s a good time to review the vocabulary that’s fundamental to understanding how football plays work.
Coaches need special lingo to save time. Short forms of terminology not only mean less talking on the coach’s part, but when the lingo is understood by the player, all sorts of symbolic associations are made that can load even more information into a simple word or phrase. The most basic example of this in football is how the spaces between offensive players are named.
For all that’s changed in football, line of scrimmage and receiver eligibility rules are pretty constant (and when they are challenged, such as by the A-11 offense, the rules catch-up and supersede any rebellious innovations.) This means that for decades, the concept of an offensive line has been as much a staple of football as blocking and tackling. Because it’s been around so long, the terminology for defining the space occupied by the linemen—the “tackle box”—is nearly as old.
The small patches of open ground between offensive linemen are the most critical spots on the field. An offense that controls these spaces can run the ball at will or keep its quarterback upright and free of grass stains. A defense that can control them, on the other hand, can stuff the run and harass an opposing passer. These spaces are so important and so frequently used that it was an early innovation in the sport to give them specialized terminology. To understand why, let’s picture a running back in the pistol formation who is carrying the ball to the right of his center:
If you were to describe this without compressed terminology, you might say something like “the halfback hits the right-side space between the guard and tackle.” It’s a mouthful, especially in a time-constrained huddle. To get around this, offensive coaches began assigning unique, fixed numbers to each of these spaces, and then referred to the spaces themselves generally as “holes.” Using the hole-system, the running back can now be told to “hit the 4-hole.” It’s short and immediately understandable.
With exception for the space in front of the center (a “zero-hole” for quarterback sneaks), the numbers correspond to spaces between or beside linemen. Even numbers are on the right side of the center and odd numbers are on the left; this means that no matter how complicated the play call is, blockers and runners will know exactly where the ball is supposed to go.
This isn’t the only numbering scheme out there, but most look almost exactly like this. The two biggest differences you’ll see are the odd/even numbers being flipped to different sides, or the “zero-hole” being left out completely or used to denote one of the spaces between center and guard (which then bumps the following odd numbers down a space.)
A very different set of terms evolved for defenders. Every defensive scheme in existence requires that some of its players be responsible for defending particular spaces between defenders. The coaches called the spaces “gaps,” and probably did so to help the defenders learn and meet their assignments. Calling them gaps meant that players who were on both offense and defense weren’t confused by conflicting terminology. To make them stand out even more, gaps were identified by letters of the alphabet. Nearly every high school, college, and professional team uses some variation of the gap system shown below:
So, if a linebacker were responsible for defending the B-gap of our hypothetical running play to the 4-hole, then that defender would be responsible for defeating the play, preferably by tackling the running back for a loss.
There does seem to be a hitch with the system since, unlike hole-numbering, the gaps are duplicated on either side of the center. This is intentional, though. Defenses react to the offensive formations presented to them, and generally do so by lining-up based on where the offense has the most players (i.e., the “strength” of the formation.) Therefore, each gap is either a “strong-side” gap or a “weak-side” gap. If the play above is being run to the strength of the offensive formation, from the defense’s perspective it would hit the “strong-side B-gap.” In college, it’s common for defenses to align according to where the ball is placed, so terminology for that can be used in conjunction with formation strengths.
You may have heard of “one-gap” and “two-gap” defenses. In one-gap defenses, each gap has a single player (usually a defensive lineman or a linebacker) assigned to defend it. In two-gap defenses, several defensive players are responsible for each defending two of the interior gaps; an example would be a nose tackle who is responsible for both of the A-gaps. Each defense has its pros and cons. The trend today on all levels is for greater and greater hybridization of schemes, where you’ll see mixes of both defensive styles on subsequent plays, or even in a single play itself, so the distinctions between the two are getting blurrier all the time.
A final item to remember is that coaches will sometimes completely do away with hole/gap references when it comes to identifying the gaps outside of the six linemen, and substitute more general terms like “off-tackle” or “alley.”