Post-scrimmage kick enforcement allows the receiving team to retain possession of the ball after they have forced the opponents to punt, even though the receiving team commits certain fouls before possession actually changes.
Normally, a scrimmage kick would be a loose-ball play, and ordinarily the basic spot for fouls during such a loose-ball play would be the previous spot.
But, under post-scrimmage kick enforcement, the all-but-one principle is still used, but it is applied as if Team R were the team in possession. The basic spot is the post-scrimmage kick spot (usually the spot where the kick ends) and the spot of the foul must be compared to that spot as if Team R were returning the ball.
Post-scrimmage kick rules apply only if all of the following conditions are met:
1) The foul is by Team R.
2) The foul (other than illegal substitution or illegal participation fouls that occur at the snap) occurs beyond the expanded neutral zone.
3) The foul takes place during the interval between the snap and the end of a scrimmage kick (not a try or successful field goal) that crosses the expanded neutral zone (Figure 11-11); and
4) Team R will next put the ball in play.
#1 After Team K snaps from the 50-yard line, R45 fields K2's punt at the R-14 and returns it to the R-35. While the kick is in flight beyond the expanded neutral zone, R62 clips at the R-20.
RULING: This foul satisfies all the conditions for post-scrimmage kick enforcement. The basic spot is the end of the kick, the R-14. Since R62's foul occurs beyond the basic spot, the penalty is enforced from the basic spot. Team B is penalized half-the-distance to their goal line, from the R-14 to the R-7. Where R45's run ends is of no significance.
#2 Team K's punt enters Team R's end zone. During the kick, R66 holds at the (a) R-12, or (b) R-28.
RULING: Since the kick ends in the end zone, the R-20 is the basic spot for post-scrimmage kick enforcement. In (a), the foul occurs behind the basic spot, so the penalty is enforced from the spot of the foul - the R-12 to the R-6. In (b), the foul occurs beyond the basic spot so the penalty is enforced from the basic spot- the R-20 - to the R-10. In either case, Team R begins their new series first and ten.