Formations
Is a tackle-over formation legal?
Short answer
Yes. A tackle-over (unbalanced) line is legal in high school, college and the NFL if the usual counts are met. The difference is the end: a tackle numbered 50-79 left uncovered on the end is legal in high school and college, where he is simply ineligible, but an illegal formation in the NFL unless he has reported as eligible.
| Alignment | NFHS (high school) | NCAA (college) | NFL | NCAA + Texas UIL |
|---|---|---|---|---|
| Tackle over, covered by a tight end (the tackle is inside the end)NFHS 7-2-5 · NCAA 7-1-4-a · NFL 7-5-1(b) | LEGAL | LEGAL | LEGAL | LEGAL |
| Tackle over, uncovered: the tackle (50-79) is the end manNFHS 7-2-5, 7-5-6a · NCAA 7-1-4-a, 7-3-3-c · NFL 7-5-1(b), (e), 5-3-1 | LEGAL | LEGAL | FLAG | LEGAL |
| Same, NFL, the tackle has reported as eligibleNFL 5-3-1 | N/A | N/A | NOT CHECKED | N/A |
High school and college: the end does not matter
NFHS 7-2-5 and NCAA 7-1-4-a list what a formation needs: enough players on the line, no more than four backs, and at least five linemen numbered 50-79. Nothing in either list concerns who is on the end.
A 50-79 player on the end is legal but ineligible: high school makes receivers eligible by position and number (7-5-6a), and college makes a 50-79 end ineligible (7-3-3-c). Neither book has reporting.
NFL: the end must be eligible
NFL 7-5-1(b) requires eligible receivers on both ends of the line, and 7-5-1(e) requires players in eligible positions to wear eligible numbers unless they have reported under 5-3-1. An unreported tackle on the end is an illegal formation, loss of five yards.
What The Playbook Caller checks
Under NFHS, NCAA and NCAA + Texas UIL the app passes an uncovered tackle on the end. Under the NFL book it flags him and says he may report as eligible instead. A still diagram cannot show a report, so the app cannot confirm one.
The Playbook Caller checks alignment at the snap only. Motion, shifts, timing, contact and penalties are not judged.
3 things coaches get wrong
- Believing "cover the tackle" is a high-school or college rule. It is an NFL rule.
- Expecting the uncovered tackle to be a receiver. In high school and college he is ineligible, whatever his position.
- Swapping a guard for a tight end to get the tackle over and dropping to four linemen numbered 50-79. That is a flag in high school and college.
Questions coaches ask
Does the tackle have to report in high school?
No. High school has no reporting. A 50-79 player is never an eligible receiver there; to be eligible he would need an eligible number.
Is a tackle over the same as an unbalanced line?
It is the most common unbalanced line: one tackle moves to the other side of the center. See unbalanced lines.
Does Texas follow the college rule here?
Yes. None of the UIL’s exceptions to the NCAA book touches the formation or eligibility rules. See Texas rules.
Sources
We paraphrase and cite; we never reproduce rule-book text. These are the public sources the verdicts rest on.
- MWFOA: NFHS Rule 7 (officials’ association)
- Referee: “Formation Consternation Demands Concentration”
- NCAA: 2026 Football Rules and Interpretations
- NFL: 2026 Official Playing Rules
Coaching aid, not an official ruling: the game officials' ruling governs. The Playbook Caller is not affiliated with or endorsed by the NFL, NCAA, NFHS or UIL, nor by Pop Warner, AYF or USA Football.
Check the formations you actually run
Drag a player and The Playbook Caller re-checks the formation under your rule book. If it breaks a rule, it tells you what is wrong and shows the rule behind it.