offense / intermediate pass
An outside high-low that places a curl behind the defender responsible for the flat.
Animated assignment view
The quarterback selects the side with the softer corner and clearer curl-flat conflict defender.
Ball: center
How it works
The outside receiver pushes vertically and returns on a curl while an inside receiver releases to the flat. The quarterback reads the outside underneath defender and uses the corner's depth to confirm the throw.
Create a dependable intermediate completion against three-deep and spot-drop zone structures.
Drive the corner vertically before returning downhill.
One receiver stops behind a defender while another runs in front of him. The quarterback throws to the level the defender leaves open.
The curl must return downhill on schedule; drifting laterally shortens the throwing lane and lets the corner overlap from above.
Decision point
The curl sits behind the flat defender while the flat route runs below him; the corner's depth confirms whether the curl window is safe.
Throw on the receiver's break when the flat defender widens and the corner stays deep.
medium riskDeliver underneath when the flat defender sinks beneath the curl.
low riskMove away from the sideline when both defenders overlap the concept.
high riskTake this concept into the film room for a direct explanation. Ask Coach Grant about this concept
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"preSnap": {
"description": "The quarterback selects the side with the softer corner and clearer curl-flat conflict defender.",
"shifts": []
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"assignments": [
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{
"id": "y-flat",
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"decisionPoint": {
"id": "read-curl-flat",
"triggerTimeMs": 2350,
"prompt": "How should the quarterback stretch the outside defender?",
"explanation": "The curl sits behind the flat defender while the flat route runs below him; the corner's depth confirms whether the curl window is safe.",
"options": [
{
"id": "throw-curl",
"label": "Drive the curl",
"description": "Throw on the receiver's break when the flat defender widens and the corner stays deep.",
"intendedRead": "The intermediate sideline window opens.",
"riskLevel": "medium"
},
{
"id": "throw-flat",
"label": "Check down to the flat",
"description": "Deliver underneath when the flat defender sinks beneath the curl.",
"intendedRead": "The defender concedes short outside space.",
"riskLevel": "low"
},
{
"id": "reset-middle",
"label": "Reset to the middle checkdown",
"description": "Move away from the sideline when both defenders overlap the concept.",
"intendedRead": "Corner and flat defender bracket both routes.",
"riskLevel": "high"
}
]
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"narrative": {
"summary": "An outside high-low that places a curl behind the defender responsible for the flat.",
"fullExplanation": "The outside receiver pushes vertically and returns on a curl while an inside receiver releases to the flat. The quarterback reads the outside underneath defender and uses the corner's depth to confirm the throw.",
"strategicPurpose": "Create a dependable intermediate completion against three-deep and spot-drop zone structures.",
"idealSituations": [
"Second and medium",
"Against Cover 3",
"Near a sideline"
],
"strengths": [
"Clear high-low read",
"Curl settles near the sticks",
"Flat provides a safe outlet"
],
"weaknesses": [
"Cloud corners can squeeze both levels",
"Late throws to the curl invite interceptions"
],
"keyRead": "Read the outside underneath defender from flat to curl, then confirm the corner has not driven downhill.",
"watchFor": [
"The receiver selling vertical",
"The flat defender's depth",
"The curl breaking back to the ball"
],
"beginnerExplanation": "One receiver stops behind a defender while another runs in front of him. The quarterback throws to the level the defender leaves open.",
"advancedNote": "The curl must return downhill on schedule; drifting laterally shortens the throwing lane and lets the corner overlap from above."
},
"simulation": {
"difficulty": "intermediate",
"conceptTags": [
"intermediate-pass",
"curl-flat",
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"baseSuccessRate": 0.59,
"yardRange": {
"min": -8,
"max": 38
},
"turnoverRisk": 0.034
}
}
Rhythm passing
Why Curl-Flat Works
Curl-flat is good football because it asks one defender a question he cannot answer twice. The outside receiver pushes vertically and comes back on the curl. The inside receiver expands to the flat. Now the curl-flat defender has to decide whether to widen with the short route or gain depth underneath the curl.
That makes curl-flat a dependable high-low passing concept against many zone coverages, especially Cover 3 and other three-deep structures. I like it on second-and-medium, near the sideline, and in situations where I want the quarterback to have a defined throw without turning the play into a one-route gamble. If the flat defender widens, the curl can settle behind him. If he hangs underneath the curl, take the easy completion in the flat and live for the next snap.
The curl receiver matters more than people think. He cannot jog to a spot and turn around. He has to sell the vertical route, make the corner respect depth, then come back downhill to the football. A late, floating throw to the curl is how an easy completion becomes a defensive touchdown.
I like this concept for teams with a quarterback who throws on rhythm and receivers who understand spacing. You do not need four sprinters. You need players who can get to the right landmark at the right time and a quarterback willing to take the answer the defense gives him. It is also a useful concept for young offenses because the read can be taught clearly: flat defender first, corner depth second.
Where I become careful is against cloud coverage or trap techniques. A hard corner who is sitting shallow can squeeze the flat while still being close enough to drive the curl. Pattern-match defenses can also muddy the clean high-low picture by passing routes instead of simply dropping to grass.
I would rather call something else if the defense is consistently disguising a corner trap, if the quarterback is holding the ball too long, or if we need a large chunk of yardage immediately. Curl-flat is built to make the defense wrong by five to twelve yards at a time. That may not make the highlight reel, but efficient intermediate passing keeps an offense on schedule and forces a defense to start changing its rules.