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Rules quiz answers and discussion
To follow along, the rules regarding ending or extending a period can be found in Rule 4, Section 8 of the 2016 NFL Rulebook.
Questions 1-3: Accepted live ball defensive foul
The most common application of this rule is when a live-ball foul by the defense is accepted. In this case, the offense can choose to extend the period by an untimed down after the penalty is enforced.
If this defensive foul happens at the end of the half or game, and is anything but a dead ball, personal foul, or unsportsmanlike conduct (this exception covered in question 10), it cannot carry over into the second half or overtime. If it happens at the end of the first or third quarters, the offense can choose not to extend the period, and simply enforce the penalty before the next period begins.
If there is a foul by the offense without a kick or change of possession, there shall be no extension of the period.
Questions 4-5: Offensive fouls before defensive possession
There are a few exceptions when the defense can request an untimed down. These exceptions are fouls by the offensive team when the defense has possession at the end of the play.
When the kicking team touches a punt before the receiving team does, it is a violation for first touching of a kick (as was the case in question 4). Note that this is not a penalty — the official (most commonly the back judge) will drop a bean bag at the spot, where the receiving team can choose to take the ball if they prefer that spot to the result of the play.
Likewise, the defense can request an untimed down after illegal touching. This is a penalty, and it happens during a free kick play: either for touching the ball before eligible, or for a kicking team player going out of bounds and coming back in bounds to touch the kick.
The other times the defense can choose to extend the period include fair-catch interference, other fouls by the kicking team during a kick before the receiving team gains possession (as in question 5), and a personal foul or unsportsmanlike conduct by the offense before a turnover (interception, fumble, or the offense failing to reach the first down on fourth down).
Question 6: Safety resulting from a foul
In question 6, since the hold occurred in the offense’s own end zone, the enforcement of the penalty includes a safety. At the end of a quarter, the next quarter would simply begin with a safety kick. At the end of a half however, the defense has the option to have an untimed down, which would be the resulting safety kick.
Question 7-10: Double fouls
A double foul is when both teams commit fouls during the play. If a double foul occurs at the end of a half, there will be one untimed down. If this happens at the end of the first or third quarters, the period is not extended. In question 7, the offensive hold and defensive facemask are a double foul; therefore there will be an extension for the replay of the down.
If there is a dead ball, personal foul, unsportsmanlike conduct, or taunting by either team at the end of the half, those fouls are enforced on the ensuing kickoff. This applies to overtime as well. Therefore in question 8, the personal foul will be enforced on the overtime kickoff.
Although a dead ball foul by each team is also a double foul, the rule includes an exception for these. If both fouls are dead ball fouls, the half is not extended. A taunting foul, even when occurring during a live ball, is always enforced as a dead ball foul. A late hit by the defense is also a dead ball foul. Therefore, there will be no period extension in question 9.
If there is a 15 vs. 5 (major-minor) double foul, and the 15-yard major foul is on the offense, the half is not extended. Any time a 15-yard foul by one team occurs on the same play as a “simple-5” by the other team, the 15-yard penalty is enforced from the previous spot. A simple-5 is a 5-yard foul without a loss of down, automatic first down, 10-second runoff, etc. In question 10, the defense committed the simple 5 (offside) and the offense committed the 15-yard major (clipping); the defense’s foul went away and the offense’s foul remains. This means there is no untimed down. The half is also not extended in a 15 vs. 5 situation if the defense’s foul is a dead ball foul.