Football 101 - MSU Pass Defense

Welcome to Football 101 – lessons in college football that, at the very least, will help you understand football Saturdays a bit better.  Screw syllabus day, lets get right to it.

The biggest concern heading into this season was the MSU pass defense.  Last year, many may remember the MSU defense making every quarterback look like a Heisman candidate as they put the ball in their receivers' hands over and over again.  Well, here's an explanation on what we do and why it should work, but didn't work last season.

The Spartans, for the most part, run a 4-3 defense, referring to 4 defensive linemen and 3 linebackers.  This is an extremely popular scheme across the country that you'll see many of MSU opponents use, as well.  Below is a diagram of the defense, lined up against a spread offense variation – which a majority of Big Ten teams use now.

Notations: DE – Defensive End, DT – Defensive Tackle, LB – Linebackers, FS – Free Safety, SS – Strong Safety, CB – Cornerbacks, OL – Offensive Line, WR – Wide Receiver, QB – Quarterback, 
RB – Running Back

Here's the general idea: 4 defensive linemen go against 5 offensive linemen.  The remaining 3 LB's, CB's, and Safeties then watch and defend the remaining 6 offensive players – the secondary (CB's and Safeties) protect against the pass normally, while the 3 LB's primarily protect against running plays.  There are exceptions to the rule, but we'll keep it simple.  In the above picture, you'll notice 4 Wide Receivers, but only 2 CB's, one on each side, to cover them.  This is where the Safeties come in.  Diagram 2 – Hypothetical situation!

In a basic play, the Cornerback will stay to the outside, and cover the receiver closest to the sideline.  On the right side of the picture, this is simple – WR runs, CB follows him.  However, on the left side, the WR's cross, and the CB has to switch who he covers to the WR heading left.  What about the other receiver heading right? It is either the responsibility of the FS or the leftmost LB to pick him up.

Specifically, what MSU's CB's do is line up about 4 yards in front of the line of scrimmage, giving a 5 yard “cushion” to the WR's (usually they're about a yard behind the line of scrimmage...that's hard math, I know).  Reason for this? The CB's usually lose a step on the WR's every play – the WR knows exactly where he's going, but the CB has to react to his actions. The only way they don't lose that step is if they're extremely good at what they do...not many Spartans are close to this category (right now).  Assuming no one screws up, this will protect the receivers from getting a deep pass for a big gain.  However, there are a few holes in this scheme:

Position 1: At the point where the WR's cross, there is an exchange – the CB picks up the WR going left, the other defenders pick up the WR going right.  At that switch point, it is necessary to have a smooth transition.  If the FS/LB doesn't notice this switch happening right away, 9/10 times it leaves a man open for a catch.

Position 2: Hey, don't know if you remember, but you know when I said it's the FS or LB's job to pick up the other receiver? Well who picks him up is dependent on where he is on the field.  If he stays closer to the line of scrimmage, the LB is on him.  If he goes further downfield, the FS keeps an eye out.  However, if a WR manages to find a seam between the FS and LB, he's got a hole to make a catch.  Ball goes over the LB's head and FS is still too far away to make a play on the ball.

Position 3: Last but not least is where MSU got burned the most last season.  Since the CB's are 4 yards downfield, it leaves the possibility for a WR or RB to catch the ball behind the line of scrimmage and proceed to run for a gain.  At that point, the only 3 players who can make that tackle quickly are the right CB, the right LB, and the SS (if he's close enough to the LB).  As you see in the above picture, there will be two WR's in front of the RB if he makes a catch.  They can then block 2 out of 3 potential tacklers.  If the SS doesn't know this is coming, then two good WR blocks lead to a big gain for the RB catching the pass.  Solution to this is the CB's and LB's must know how to get around blockers quickly and be able to react quickly.

However, what if no one screws up?  Or the QB doesn't recognize one of the three options that would work?  Why did MSU get burned?  The problem lies at the line of scrimmage.  Next picture!

Remember that there are 4 Defensive Linemen trying to get by 5 offensive linemen to get to the QB.  Just like I said between the WR's and CB's, the OL's have to guess where the DL's are going to prevent losing a step and their man getting by them.  Usually, someone on the Dline can beat their man and get to the QB...MSU couldn't do that last year.  Gave the QB enough time to find an open receiver and get a gain.  Solution for the Spartans? They had to blitz, ie send a LB or two towards the QB to generate some pressure.  This leaves the position 2 very vulnerable to the pass.  Any non-blitzing defender who tries to defend that area loses their assignment so an obvious hole opens up elsewhere.

Here’s a real world example that is somewhat relevant: 2009, MSU vs. Iowa.  Here is the setup for the last down:

In this case, you can see pretty much everyone blitzing in to try to pressure the QB.  Positives? Probably going to scare the crap out of him into making a mistake, or sack him within 2 seconds, if it’s a passing play.  If it’s a running play, no chance the back gains a yard.  Negatives? No one can help pick up a receiver if a CB loses a step.  At the top of the screen, without a LB left to help the CB, QB Ricky Stanzi is able to get it to his WR immediately.  Ball game, MSU fans enjoy drinking their sorrows away.

There you have it.  Although the MSU scheme prevents a deep pass in most every situation (unless someone screws up), it allows an opponent to make short passes continuously all the way down the field.  The idea is that at some point, the QB will screw up, or close to the end zone there is so little room for the WR's to work that they'll be unable to find a seam.  The key is getting more penetration along the lines.  If they can do that, then the pass defense will be significantly better and more success will come.

Next week, I'll cover the recruiting aspect for MSU and how that translates into performance on the field.  Thursday will be some national and Big Ten news, while Friday will be the preview for the MSU – Florida Atlantic game at Ford Field this Saturday.  Thanks for reading!