Blunt force.
Those two words epitomize the personality of the Iso play. For most I-formation and traditional pro-style offenses, Iso is one of the first plays installed. Think Earl Campbell, Christian Okoye, and Brandon Jacobs; the ultimate power back coming downhill right now, and the car crash is going to happen whether you like it or not. That’s Iso.
What is the Iso Play?
Iso is a downhill running scheme that utilizes a Fullback as a lead blocker on a linebacker with multiple base blocks and double teams at the point of attack. It’s a concept designed to overpower a defense and get the ball vertical as quickly as possible.
The play is called "Iso" because the lead blocker is "isolated" in one-on-one with the linebacker as a lead blocker.
What are the Strengths of the Iso Play
One of the best attributes of the Iso play is that it gets the ball downhill FAST. The Tailback is taking one step, getting downhill, and he isn’t getting off of that vertical track until he gets passed the second level of the defense. For any offense that has a bruiser of a Taiback and an Offensive Line that’s capable of sustaining 1-on-1 blocks, Iso is about as consistent of a yardage-gainer as there is.
A second strength of the Iso concept is its simplicity. The reason that it was such a common scheme in playbooks around the country is that it was very easy to teach. When a concept is easy to teach, the players are able to go and execute at a high success rate.
What are the Weaknesses of the Iso Play?
The biggest weakness of Iso is the fact that it is relatively dependent on personnel. Most teams that decide to run Iso have large, powerful Offensive Linemen that are able to dominate 1-on-1 blocks at the line of scrimmage. They’ll also have a rugged Fullback who’s able to take on a linebacker in the hole with a 5-yard head start. Teams with smaller, weaker Offensive Linemen are going to have less success with this scheme due to the reliance on being able to block defenders 1-on-1.
Iso Play vs 3-4 Odd Front
Left Tackle - Drive block on the backside edge defender. Establish and maintain inside leverage
Left Guard - Drive block on the Defensive End. Establish and maintain inside leverage
Center - Double team with the RG on the Nose Tackle to the backside Inside Linebacker. Attempt to bring the Nose Tackle over to the backside A-gap and allow the RG to climb to the second level
Right Guard - Double team with the Center on the Nose Tackle to the backside Inside Linebacker. Drive the Nose Tackle to the backside A-gap and climb to the second level
Right Tackle - Take an initial inside step to establish inside leverage, then drive the Defensive End vertical
Tight End - Take a drop step toward the playside edge defender with a near-shoulder aiming point. Establish and maintain inside leverage
Fullback - Step off of the midline by stepping with the right foot first, then get vertical with the second step. Search for the open space (the playside A and B gaps in this case) and square up the playside Inside Linebacker. Strive for the near shoulder
Tailback - Step off of the midline with the right foot, then immediately get downhill with the second step. After receiving the handoff, follow the Fullback and burst toward the leverage he has at the second level (i.e. inside leverage, burst by his inside hip)
Quarterback - Reverse pivot and extend the ball with the left hand to execute the handoff
X Receiver - Climb for the near Safety
Z Receiver - Climb for the near Safety
Iso Play vs 4-3 Even Front
LT - Drive block on the backside edge defender. Establish and maintain inside leverage
LG - Combination block with the Center on the Nose Tackle to the backside Inside Linebacker. Work for verticality with eyes on the Linebacker to determine who comes off of the double team
C - Combination block with the LG on the Nose Tackle to the left Outside Linebacker. Work for verticality with eyes on the linebacker to determine who comes off of the double team
RG - Combination block with the RT on the Defensive Tackle to the right Outside Linebacker. Work for verticality with eyes on the linebacker to determine who comes off of the double team
RT - Combination block with the RG on the Defensive Tackle to the right Outside Linebacker. Work for verticality with eyes on the linebacker to determine who comes off of the double team
TE - Take a drop step toward the playside edge defender with a near-shoulder aiming point. Establish and maintain inside leverage
FB - Step off of the midline by stepping with the right foot first, then get vertical with the second step. Search for the open space (the playside A gap in this case) and square up the Middle Linebacker. Strive for the near shoulder
TB - Step off of the midline with the right foot, then immediately get downhill with the second step. After receiving the handoff, follow the Fullback and burst toward the leverage he has at the second level (i.e. inside leverage, burst by his inside hip)
QB - Reverse pivot and extend the ball with the left hand to execute the handoff
X Receiver - Climb for the near Safety
Z Receiver - Climb for the near Safety
Variations
Now let's take a look at some popular variations of the iso play.
Variation #1: Shotgun Iso
During the early 2010s, Art Briles and Baylor had one of the most explosive offenses in college football history. One of their foundational plays was Iso from the Shotgun. This allows for a Spread offense to have a downhill running game without having to read a defender. As could be seen with Baylor, this Iso scheme was usually accompanied by some variation of an RPO.
Variation #2: Weakside Iso
Iso is generally ran to the strong side of the formation; however, it doesn’t always have to be that way. In the example above, the Offensive Line is able to establish two double teams on more favorable angles compared to the strong side Iso. Rather than block the Middle Linebacker, the Fullback blocks the left Outside Linebacker.
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