How a 4-3 defensive front works, including personnel groupings:
A 4-3 defensive look has two defensive ends and two defensive tackles. Behind them is a middle linebacker commonly called the "Mike" linebacker. Flanking him are two outside linebackers. They're commonly referenced as the "Will" and "Sam" linebackers. The title "Sam" means strong side of the offensive line (right side). Essentially, the Sam linebacker lines up across from the Tight End when he's on the line of scrimmage. The "Will" linebacker is usually positioned on the opposite side of the Tight End over the opposing teams Left Offensive Tackle.
Both the 3-4 and 4-3 have different goals at each level of the defense. From the research I was able to do, the defensive line on a 4-3 seems to be a lot more "undisciplined" in the sense that they have their gap assignments (shown below) that they have to monitor between each offensive linemen (A-C Gaps). If the DLine can, they should penetrate a specified gap to make a play in the backfield. Usually defensive ends (DE) are asked to maintain the C Gap and make sure the quarterback does not break contain of that gap (i.e get outside). If the defensive end has the opportunity to rush up the field and get a sack, it is encouraged. The defensive tackles (DT) are asked to "hold the point of attack" which means to occupy the offensive guards and center as well as the B and A Gaps. If they see a pulling offensive Guard/Center it is encouraged that they rush through his vacated gap and make a play in the backfield.
Linebackers in this system usually play more coverage on Tight Ends (TE) due to the fact that there are already four rushers in front of them. The defensive line helps take up more offensive blockers so on run plays linebackers are tasked to "clean up the mess" (i.e find and tackle the ball carrier).
I understand if the above seemed dry and I do apologize, the point was to explain the basics of the 4-3 System. The personnel that fit each system however, is very interesting and vastly different. For a 4-3 look to be used optimally often time's undersized linebackers are used because they can run side line to side line quicker than lumbering big guys, they usually weigh 220lbs to 230lbs in college. Defensive tackles usually weigh in the low 300s because they're asked to be quick to their gap coverage or penetrate into the backfield. The defensive ends are usually slight in size too at about 260lbs, this is due to the fact that speed moves are an effective way to get into the backfield and are usually the quickest way to disrupt the play.
How This Play Style Effected Miami:
When studying old UM games (pre 2010) Miami ran a hyperactive, blitz crazed 4-3 system. Coach Shannon and his predecessors were able to use the speed from the local area in their personnel packages and essentially "blitz the gaps" in the offensive line (think of a track runner in the blocks ready to run at the sound of the start gun). Now, this very much is a boom or bust strategy. If you get to the running backs or the quarterback before the play develops then you have a negative yardage play. However, if a player doesn't rush his specified gap whether it's through a mental mistake or physically not being able to win his battle, holes open up and huge plays can happen. Due to the speed at Miami the term "Miami Speed" was coined. You'll often times hear this phrase used if a team runs a toss sweep to the running back wide of the C Gap. With UM's speedy linebackers they used to be able to penetrate and hit the running back before the play developed.
(W)OLB MLB (S)OLB
DE DT DT DE
C (T) B (G) A (C) A (G) B (T) C (TE)*
* Offensive linemen/Tight End
How a 3-4 Defensive front works, including personnel groupings:
The 3-4 Defensive Front compared to the 4-3 often times is believed to be more complex and difficult for offensive lines as well as quarterbacks to read when it involves who is going to rush the quarterback on any given play. In theory, when you see four down linemen probably 8 out of10 times those 4 will rush the line of scrimmage. However, in a 3-4 front you don't know if the three down linemen are coming, if one or both outside linebackers are blitzing or even if the inside linebackers are charging the A or B Gaps. This makes identifying schemes a chore for the offense. The reason the 3-4 front is not run more frequently is because it can be a very rigid defense to learn for the players and the installation of it often takes a few years due to getting players to fit the system physically.
The Defensive line on a 3-4 has two Defensive Ends who often times weigh between 280- 300 lbs. They're main responsibilities are to have gap coverage and take the attention of the offensive tackles as well as the guards. The Defensive Tackle (commonly called a nose tackle) is arguably THE most important position on the defensive side of the field. They're asked to disrupt the Center, A Gaps and make their presence known to both Guards. This position is extremely demanding and often times hard for defenses to fill because the players have to be very large (330lbs is optimal size), be able to maneuver the interior offensive line with cat lick reflects and the person has to accept that he may not garner much attention statistics wise. The theme overall for the defensive line is to occupy offensive blockers so that the linebackers can cause disruptions in the backfield.
The outside linebackers are tasked with one of two responsibilities. 1) To rush the quarterback or 2) play in coverage. If a team has one elite pass rusher (i.e Demarcus Ware type) he is called a "Joker" and usually rushes from anywhere along the defensive line; even sometimes coming as a defensive end on obvious passing downs. Sometimes however, teams don't have an elite pass rushing outside linebacker so teams usually split up that responsibility between the two players. They're called "Jack" and "Elephant" linebackers if that's the case. The typical size of an outside linebacker can range from 235-245lbs at the college level.
Even though there are two inside linebackers (ILB), don't let their positions fool you. Both have dramatically different roles within the defense. The "Mike" linebacker (same name as the 4-3 equivalent) is the quarterback of the defense due to the fact that he lines everyone up and gets them in their proper gap assignments which cannot be overstated or undervalued in an effective system. A Mike linebacker usually drops into coverage and makes plays in the running game by going sideline to sideline. He is usually 230-240 lbs (a great example is the ageless wonder London Fletcher). The "Ted" ILB can best be described as a bowling ball of mayhem. They usually are tasked with blitzing the interior of the offensive line, usually to disrupt pulling guards and making life for the center miserable. These unique players are usually 235-250lbs.
Line backers OLB I LB I LB O LB
Defensive Line DE NT DE
Offensive Line C (T) B (G) A (C) A (G) B (T) C
How This Play Style is Effecting Miami:
Miami historically has been a 4-3 defensive front. When Golden and his defensive staff came onboard they slowly started to change the personnel and the playing packages that we've seen on the field the last two years. The transition has been painful due to two main factors: players being too young who were just brought in and players not fitting the system due to the previous regime's use of the 4-3.
Golden's defense statistically the first season was average. The reason was because he was able to adjust his defensive philosophy to the players he had and be somewhat successful when it came to shutting down opponents and causing turnovers. However, after his first year on campus, many players decided to transfer or were thrown off the team and this left a tremendous talent vacuum as well as an overall lack of players in game shape to contribute. Due to the mass exodus, as we all know, the bottom fell out for our defense last year. Many players were asked to play before they were ready (mentally) and some were asked to play and just couldn't execute their assignments (physically) of gap control which made the defensive line ineffective and opened up massive running holes and passing lanes for the quarterbacks.
With the last two years behind us and Golden moving into his third year at the helm, players are starting to develop along the defensive front 7. The defensive line depth averages close to 300lbs and we now have our first 320lbs defensive tackle that is at full strength (Curtis Porter). On the linebacker level we have coverage guys that average a solid 235lbs and have game experience (Perryman, Gaines, Figatron, Ambrister, Kirby and Cornelius) as well as a few guys who can rush the passer (McCord and now Gilbert).
Make no mistake, Golden may upload depth charts that list UM as a 4-3 defense but if you watch game film it is pretty apparent UM is running a 3-4. It has been a few years in development due to getting the right players in positions as well as just adding bulk to the roster, but it looks like UM may be able to unleash their own version of the 3-4 defense on the ACC.
How long until the FAU game?