As the game of football has evolved over the years, so too has the position of quarterback. The sport has gradually transitioned away from the sturdy pocket presence signal-callers toward a newer, more dynamic breed: the dual-threat quarterback.

One has to look no further than 2019 NFL MVP Lamar Jackson to see the nightmares that a dual-threat quarterback can give opposing defenses. No longer does a defense simply have to account for a quarterback’s arm; it must also account for his feet — quarterbacks now look to extend plays by leaving the pocket and often take off if their receivers are covered downfield.

And as the quarterback position has evolved, so too have offensive playbooks. Perhaps one of the best examples of a scheme designed specifically for mobile quarterbacks is the read option: the play that TCU quarterback Max Duggan executed to perfection late in the fourth quarter of the Horned Frogs’ win over Cal on Saturday.

Let’s break down how a read option works. First, the quarterback must read the defense. The opposing team’s outside linebacker is intentionally left unblocked so that he has a free pass at either the quarterback or the running back. Then, seeing where the linebacker is headed, the quarterback must choose between two options: hand the ball off to the running back or fake the handoff and keep it himself to run, as all of his other targets are already assigned to block downfield.

Duggan, who has been lauded for his abilities as both a passer and a runner, was well aware that he had the Bears’ defense on its toes. After all, Duggan had already thrown for three touchdowns to that point, and with TCU knocking on the door again from Cal’s 9-yard line, the Bears’ defensive backs were playing far off of the line of scrimmage to prevent another passing touchdown.

But Duggan wasn’t the only one the blue and gold had to account for. Sophomore running back Zach Evans, one of the most prolific rushers in the nation, had already gashed Cal’s defense with a 51-yard touchdown run in the second quarter. Certainly, Evans, who finished the game with 190 yards on the ground, was a candidate to get a carry on first-and-goal.

And so, the Horned Frogs smartly opted to run the read option.

With 5:53 left in the contest and TCU clinging to a 1-point lead, a touchdown (and successful PAT) would ensure that the Bears couldn’t do more than tie the game. On first-and-goal, the Horned Frogs left Cal outside linebacker Cameron Goode untouched off of the edge as their left tackle double-teamed the Bears’ interior lineman. The decision forced Goode to choose between pursuing Duggan and Evans, who stood next to each other.

When it was clear Goode was going after Evans — eventually tackling him into the ground — Duggan faked the handoff and tucked it under his arm. TCU decided to line up two receivers on the right side to offset Cal’s defense before the snap, leaving plenty of space along the left side of the field. Strong blocking from the Horned Frogs’ receivers on the perimeter meant the only people with a chance of tackling Duggan were the Bears’ two linebackers, Evan Tattersall and Mo Iosefa, and cornerback Joshua Drayden.

A delayed block from TCU’s center on Tattersall took the linebacker completely out of the picture. Similarly, the Horned Frogs’ left tackle, after initially double-teaming on the interior, kicked out and stonewalled Iosefa. That left only Drayden to make the tackle, but he was too late to react as Duggan sprinted up the left seam. One cutback later, Duggan was diving into the end zone and beating his chest in celebration.

It is hard to blame Cal for failing to make the stop. But when you step back, you realize that the play was only made possible by the Bears’ defensive mistakes earlier in the game. If Evans and Duggan had been kept in check earlier, Cal would not have been in that situation. And if Duggan had not scored on that play, maybe the Bears wouldn’t have a measly 2-0 record to show for.