Ol' Norm Parker, God rest his soul, had an impact on the art of defense that still lives strong today. Parker's Iowa Hawkeye defenses were renowned for their willingness to line up in cover 2 over and over again and just beat people up with good fundamentals. Like a less aggressive version of Narduzzi's Spartans, they trusted in a mastery of their own defense to bring them victory over opponents trying to game plan specifically for their scheme.
The heart of cover 2 defense is how it utilizes two deep safeties playing deep zone coverage to prevent any big plays from the offense. In today's era of cover 4/quarters defense there are many teams that line up in a two-deep safety shell but then use the safeties as active participants in their run fits.
A favorite cover 4 scheme of today is one that plays the boundary safety aggressive in run support. The result is an eight man front with big, physical DBs "overhanging" the perimeter in position to bring quick run support:
But this style is not classic cover 2 or "bend don't break defense" of the sort that Norm Parker utilized with Iowan farm boys while shutting down offenses from around the country. The corners have to be able to hold up in man coverage without deep help and the safeties often drop down into the box rather than sitting in deep zones.
Last year's number one defense both in overall and passing S&P was the Clemson Tigers, and they did it in part by taking a page from Parker's book and playing a more conservative style of defense which kept both safeties back more often than not. In particular, they played a lot of cover 6, which is essentially cover 2 modified to handle the spread offense:
The defense might handle route distributions to the field in a variety of ways or even play a different type of coverage on that side of the field, but the key is that the safeties are in deep alignments when the ball is snapped and are only support players rather than primary run defenders.
The boundary corner is the essential ingredient to this defense since he needs to be able to press the receiver, take away the quick routes, and then force the run. If he can do that effectively, the safety can play deep and make it very difficult for the offense to execute any explosive plays since he'll always arrive to clean things up before the situation gets too dire.
Clemson relied on Garry Peters in this role in 2014 and he rewarded them with eight tackles for loss, two sacks, 12 pass break-ups, a forced fumble, and the ability to move safety Robert Smith around and disguise coverages. In fact, with Peters on the boundary the Tigers could line him up in press coverage and play either of the above coverages with the safety dropping down to outnumber the run or sitting in a deep zone without tipping their hand.
The versatility of Parker's bend don't break cover 6
What makes this style of defense a viable strategy in the college game is that, if the boundary corner is strong in run support, it's actually a reasonably strong run defense despite playing a deep 1/2 safety.
For instance, offenses often like to challenge this defense with a "trips closed" formation that combines extreme stress to either side of the field:
With the running back and tight end aligned to the boundary the offense's strongside when running the ball is to the boundary, but the three removed receivers to the field make that the strongside for the passing game.
Offenses often try this formation against cover 6 teams because they force the defense to shade the middle linebacker (or one of the linebackers, depending on how the defense aligns them) out of the box and basically force the defense to replace him with the boundary cornerback.
However, in reality it doesn't always play out that way if the corner is actually physical enough to get the job done and the safety is triggering downhill quickly when he sees the tight end run blocking rather than releasing to run a route. Add in a middle linebacker that has range and you end up with eight hats getting to the football pretty quickly, it's hard to do much better than that schematically.
But teams don't play cover 6 because it's a dominant anti-run scheme, they play it because it can murder college passing attacks. College teams love to attack with the boundary receiver and will often use trips formations to get the defense to roll the defensive backs away from the boundary so they can throw to their best receiver against man-to-man coverage.
Cover 6 teams will yield some advantage to the trips side and maintain their hi-low bracket coverage on the single-side receiver, eliminating him from the game.
Texas A&M loves to use spread trips formations to get their outside receivers isolated on corners, but Mississippi State wouldn't bite and kept that receiver bracketed in cover 2 throughout the game:
The result was that Kenny Hill had to work primarily to the field with long, difficult passes. He threw 62 times but generated only 365 passing yards, good for 5.9 yards per pass attempt, with four touchdowns but also three interceptions. While the number of passing yards and touchdowns are high, that kind of inefficiency will get a spread passing team beat up if they don't play great defense, which the Aggies didn't.
Mississippi State's DC Geoff Collins was famous for his "mayhem" defense that he's now bringing to Florida under Jim McElwain, but his charges generally produced "mayhem" by playing conservative cover 6 defense on standard downs, rallying to the football to stop big plays, and then bringing pressure in obvious passing situations, just like Norm Parker's Hawkeye defenses. Collins simply has more of a flair for marketing his conservative approach so that it sounds like an aggressive and wild scheme rather than something rather classic and fundamentals based.
The boundary corner skill set
Clemson is now moving on from the Garry Peters era and whether they'll have another corner who can play press coverage and be a physical force player on the boundary edge remains to be seen.
Clemson returns Mackensie Alexander, a lockdown corner who's dominance in coverage may encourage DC Brent Venables to play him on the boundary so they can roll the boundary safety over or drop him down into the box rather than playing Parker-style bend don't break. Or they may leave Mackensie on the field side so they can continue to bracket the weakside in cover 2.
Some teams that like to play cover 6 on run downs (most teams mix it in on passing downs) don't define their corners as "field" or "boundary" so they can avoid having to ask their corners to flip sides on the field when facing up-tempo attacks. For teams that play their cornerbacks as "left" or "right" they'll generally play the corner they feel is the better force defender as the "left" corner since right handed QBs often throw to that side of the field which results in the left cornerback playing on the boundary more often than the right corner.
This is especially common amongst cover 3 teams that mix in cover 6 as a change of pace. The Oklahoma Sooners played with left and right cornerbacks in 2014 but strangely played their converted safety and superior run support player, Julian Wilson, as the right corner while playing the slight of frame Zach Sanchez as the left corner. This inevitably lead to many situations where Wilson was out-matched trying to cover quicker athletes in space while Sanchez was getting beat up by bigger players.
Florida State is moving Jalen Ramsey to the boundary which will allow them to mix in this bend don't break style or to roll coverage away from him because he is such an effective player when isolated in man coverage.
The ideal boundary corner is a big, versatile player like Ramsey or Peters who can allow the defense to trust him in man coverage so they can aggressively outnumber the offense at another point on the field OR play the edge against the run and allow the defense to bracket the boundary with cover 2 and make it unassailable.
The physical element is particularly key with two schemes that every boundary corner is likely to encounter, the first being defending gap schemes run to that side of the field:
Assuming that the corner can get off a block from a big outside receiver, they also need to be able to play blocks from pulling linemen on schemes such as this pin and pull play. They don't have to blow up the guard but they do need to keep the ball inside of them and ideally meet the guard as close to the action as possible so the rest of the defense doesn't have to cover much ground to track down the RB.
The boundary corner also ideally adds something on the blitz as he's one of the better positioned defenders to blitz the QB since he's both in close proximity and also isn't a guy the QB is necessarily aware of due to the wide angle.
A boundary corner that be physical enough to allow that kind of blitzing and run support on the edge makes Norm Parker's vision possible. If he can also play man coverage without safety help, even better.
2015 Norm Parker champions
There are a number of teams who are likely to run cover 6 in 2015 on run downs and carry the legacy of Parker's bend don't break" philosophy.
The Penn State Nittany Lions are a team that regularly play cover 6 and have added the similarly designed tampa-2 scheme to their base package. They'll probably look to utilize sophomore Grant Haley on the boundary and trust safety Marcus Allen to provide timely run support behind him.
Kansas State has the ideal boundary corner in Danzel McDaniel to allow them to pursue this strategy which will be useful as they look to plug in an underclassmen at free safety. At 6'1" 205 with a nasty disposition and love of press coverage, McDaniel is a fantastic fit for this scheme.
In the SEC, both Mississippi State and Arkansas have recently used and will likely continue to use this style of defense. Arkansas' DC Robb Smith likes to be able to take away what offenses do best and there are few better ways to squeeze a passing game than with this approach. What's more, the Hogs return both their boundary corner D.J. Dean and strong safety Rohan Gaines.
Mississippi State will continue to play "2-read" coverages under Manny Diaz as it serves as an ideal base defensive complement to his extensive fire zone package. One snap you're facing an overload blitz, the next his charges are dropping back in cover 2, big passing plays become hard to come by.
Finally there's Ohio State, who played a lot of true two-deep defense as well in 2014 but have to find a replacement for boundary corner Doran Grant who was very effective down the stretch for them.
Offenses are evolving and growing more proficient all the time, but there's still some lasting influence from Norm Parker's style of still simply lining up and daring opponents to get their yardage the hard way.