Football terminology is something native to football coaching. To the non-coach, it is not. Cover 1, Cover 2, Cover 3, Tampa 2, 46 Bear, etc.; all this can often be quite confusing. The purpose of this article is to describe in a limited sense what is exactly meant when one discusses the term "Cover 2" as it relates to a defense.
In its generic sense, the term "Cover" does NOT indicate a particular defensive scheme. Rather, it describes the coverage responsibilities of the safeties. One must remember that the safety(s) are the last line of defense between the offense and the goal line. Ergo the term "safety." Regardless of whether the the play is a run or a pass, the safety must place himself in a position which keeps himself between any opposing player and the goal line. The exception is within the red zone, where (depending on the location of the snap) the field responsibilities collapse, requiring a shift in both run and pass assignments.
Different defensive schemes favor particular base safety coverage responsibilities. The traditional 4-3 defensive set is considered to be a Cover 2. This defense, revolutionary at the time, was developed by Tom Landry when he was the the Giants' defensive coordinator in the 1950s. It evolved out of the earlier "Unbrella Defense," as designed by previous Giant HC Steve Owen. In the (then) modernized Landry 4-3, the weakside (free) safety plays back, 12-15 yards off the line, while the strongside (strong) safety plays about 8-10 yards off the strong side of the line. Quite often, the strong safety has man coverage on the tight end. In such man-2-man coverage, the defense is in a Cover 1. Otherwise, the SS has deep coverage to the strong side. This style of defense remains the base 4-3 scheme to this day. To avoid confusion, I like to refer to this safety coverage as a "Cover 1 1/2," as the strong safety cheats up closer to the line.
As used in today's terminology, a "Cover 2" utilizes the safeties in cutting the deep field coverage responsibilities exactly in half between the two safeties. Both safeties play equally back, with neither cheating up closer to the line. This allignment, whether called a "man" or a "zone" coverage, is in fact a zone responsibility. Each safety gets exactly one half of the deep area of the field to protect. A Cover 2 expects the front nine of the defense to take care of all play in front, with the safeties free to react to the play as it develops.
A Cover 2 does not indicate the aggressive strategy of a defense. Bill Parcell's 3/4 Giant defense of the 1980s utilized a Cover 2. Parcells' defense was to two gap in the up front interior of the line and a lateral coverage to the outside. This was a run stop first defense that dealt with the pass via viscious blitzes from multiple angles, press man-2-man on the corners, and a Cover 2 to prevent getting beat deep on a run or a pass. In Parcells' defense, the corners had big time run stop responsibilities. It was not uncommon for a corner position to record 100 tackles in a season. As stated, the corners were thus required to play up close to the line in a press m2m. Parcells had outstanding personnel to play this defense, particularly at the linebacking positions. Besides LT, Carl Banks was a great cover linebacker who could stay with the tight end, allowing the strong side safety to deep zone the strong side of the field. And interior linebackers Gary Reasons and Harry Carsons were rock hard tacklers and good coverage linebackers who played their responsibilities almost flawlessly.
To the opposite end is the "Tampa 2." This defense is a particular style, or scheme, of defense which also utilizes a Cover 2. The Tampa 2 is straight up unagressive zone form of the base 4-3. The biggest difference between the "Tampa 2" and the traditional "Landry 4-3" is how the linebackers are utilized in coverage. The corners, who have outside responsibilities, actually play an outside technique, feeding the wide recievers to the middle. The outside linebackers cover the short outside routes. The middle linebacker has the middle of the field, from short middle to about 25 yards deep. The pass rush is the responsibility of the front four. The Tampa 2 was developed by Tony Dungy when he was at Tampa Bay. He brought it with him to Indianapolis, where it is still utilized. The Tampa 2 blitzes less than any other defensive scheme. Since Dungy went to the Colts, they have blitzed less than any other team in football.
I will expand on the "Cover" concept in future posts, later to be combined into a single, unified article.