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Georgia Tech Football: Film School - 4-2-5 Base Defense

Let’s examine our typical defensive lineup and its advantages

COLLEGE FOOTBALL: SEP 08 Georgia Tech at USF Photo by Mark LoMoglio/Icon Sportswire via Getty Images

I want to take this article back to basics. In my travels, I have come to realize most people understand offense and its formations and strategies. But few understand defense. They see blitzes and interceptions but don’t understand how any of that comes together.

This is going to be a beginner level course for those and hopefully a refresher for our more initiated followers.


We run a “4-2-5” base defense which consists of 4 defensive linemen, 2 linebackers, and 5 men in the secondary. There are usually 2 corners, 2 safeties, and a “nickel-corner” on every play. It’s important to distinguish this nickel corner and talk about what makes them special. With the advent of spread offenses, many teams began running some hybrid of this defense and many teams use it as their standard defense. (Ohio St, West Va, TCU, Alabama, and Georgia Tech to name some examples)

Substituting a linebacker for a safety/corner allows teams to better cover the slot and be more agile as a team. Unless we are facing a football team who likes to run power football, you will see GT in this base 90% or more. A distinguishing feature of this defense is faking a huge rush, bringing one side heavy to the QB and dropping your weak linebacker into coverage.

Point is, there are rovers now, they can be a prototypical strong safety or a shorter corner. The Alabama playbook calls them Star or Apex. I’ve heard them called Rover or Joker.

History on the Flats

It’s hard to nail down defensive history because, besides opposing coaches, no one sits down and writes out every formation and play in a reference book. But we are able to look back at previous coordinator’s style

Current DC Andrew Thacker
Official Portrait. Courtesy GT Athletics,

Incumbent: Andrew Thacker - True Nickel 4-2-5

Courtesy SB Nation/

2018: Nate Woody 3-4 base

Courtesy SB Nation/

A hallmark of 3-4 is outside linebacker blitzes. Usually a more aggressive approach that relies on pressure to force “defensive disruption”

2013-2017; Ted Roof 4-3 Multiple

Courtesy: SB Nation

No one around here remembers Ted Roof fondly. There was at least one bitter bubble screen reference in the prep for this article internally and Ol “bend but don’t break” Ted caught a lot of flak for letting his defenses get filet’d regularly.

Ted actually employed some nickel formations but it was less than 50% of the time. Usually only on obvious passing downs or desperate comebacks. Like this disaster:

Miami at Georgia Tech: 2014
Credit: SB Nation/

2010-2012: Al Groh 3-4

2008-2009: Dave Wommack 4-3

That’s as far as I’m willing to go back but we’ve had a lot of change at the DC helm and it always seems to be 2-3 years of rebuild with zero payoff. The philosophy change and position changes from switching are jarring to individual players and the misfits show on the field.

Georgia Tech hasn’t placed better than #28 in Scoring Def in those 12 years of football (‘08). Really hovering around the 60s in ranking. 2019? We were 104th out of 130.

In case you were wondering, 1985 Blackwatch under DC Don Lindsey? 4-3. (I had to watch old film to find that out. Take a trip through time with me. This broadcast is incredible: #8 Auburn at GT, 1985)


On any given play, each defender has an assignment. You are usually doing one of two things, rushing the passer or dropping into coverage. I want to talk about coverage first because it informs which defenders are free to blitz.

Let’s go back to nomenclature. Ever hear Cover 2 or Cover 0 and wonder what that actually means? “Cover” on a play sheet means the number of DBs dropping to deep zone coverage. They are lurking back looking for deep routes. This is usually reserved for safeties and the most common coverage is “Cover 2”

Courtesy: SB Nation/Daily Norseman

Let’s count up from zero. Cover Zero means you are lining up man coverage on your 5 eligible receivers and blitzing everyone else. It’s aggressive and sometimes called man blitz or all out blitz. It’s not actually all out but it is very risky. This usually rattles inexperienced QBs and even veterans see their numbers dip against high pressure. Telltale sign? DBs playing right up on the line.

Cover 1 is usually obvious and sometimes disguised as cover 2 (called Robber). A deep free safety and corners on the line, probably a lurking linebacker over the middle, and a 5 man rush. A common tactic in 4-2-5 defense is to show pressure/blitz and drop one of those LBs into coverage suddenly revealing an intense pass rush to the right or left. The point is to overload one side vs the other and catch those linemen on their heels. MLB David Curry is your fake blitzer here:

We have gone over Cover 2 but it is the most common. Typically rush all 4 down linemen, put your linebackers in short zones and man-to-man outside corners, two deep safeties.

Cover 3 or more always means pulling guys from blitzes or underneath coverage. You can slow down an explosive offense this way but give up lots of 5 yard runs and passes * cough * Ted Roof * cough *. In this scenario, that versatile nickel corner is probably covering over the middle. Telltale sign: Deep corners and FS in middle of field.

4-3 version of Cover 3
Courtesy: SB Nation/Cat Scratch Reader

That Nickel corner is a prototype as well. You want to find someone with the size and abilities somewhere between a linebacker and a strong safety. On any given play, they can act like a third linebacker or third cornerback. Its a very interesting role. Kaleb Oliver was the starter down the stretch last year yet former LB Charlie Thomas has switched over to the role and looks very promising.

Pass Rush

Try to imagine the 4 defensive linemen as a solid unit. In all the film I’ve watched of 4-2-5, almost never do you see any of these 4 drop into coverage, always pass rush. You can have gigantic DLs because they always push their weight forward to the QB or runningback. There are 2 Defensive Ends meant to rush the QB from the outside. These are prototypical edge rushers you see in the league. There are also 2 Defensive Tackles who’s primary objective is to push the OL backwards, take up space and create havoc, stop the run if its coming.

You often see these DTs called 1-Technique or 3-Technique. In the diagram below you’ll see these are the names of the gaps but it really should be called inside DT/Nose Tackle and outside DT. Typically the biggest starting DT is your 1 Tech and your slightly more versatile DT is 3 Tech.

Courtesy: SB Nation/Big Blue View

Pro Tip: Linebackers are often separated into “Sam” “Mike” and “Will”. The common man just calls these Strongside LB, Middle LB, Weakside LB. The strong side is where the TE lines up or where they overload the OL, it’s almost always the right side of the offense.

Now, any number of people can blitz here because of the versatility of the nickel corner. The Nickel “Rover” can cover the middle while the two “Mike” and “Will” LBs blitz or act as a 3rd linebacker and blitz outside while your typical two LBs cover the middle. Example of Nickel Corner Blitz:

That’s all I have for today. I hope you learned something about defense and what to expect in 2020 on the Flats. GT will line up lopsided most of the time but you’ll be able to understand what is going on.

64 days to kickoff.