In the aftermath of Alabama's loss to Ole Miss on Saturday, discussion has been rekindled around the POP pass and its exploitation of the ineligible receiver downfield rule. For those unfamiliar with the current rule, offensive linemen are allowed to be no more than three yards downfield at the time a forward pass is released. Having an arbitrary window like this makes it difficult for the officials to police, as the difference between three yards and four yards can be difficult to ascertain depending on the official's angle. This inspired a failed rule proposal in the offseason to remove the three yard window and adopt the NFL rule, which allows linemen to advance no more than one yard before the pass is thrown. Proponents of spread offenses argued for better enforcement of the existing rule as opposed to a rule change, suggesting that such a rule change would take an exciting play out of college playbooks.
In reality, the POP pass similar to the one seen in the Ole Miss game (pictured above) and near the end of the 2013 Iron Bowl is only a small part of the issue. The more liberal college rule creates an entire offensive concept that is unavailable in the NFL - a true run-pass option, or RPO. When fans hear RPO, they often think of roll-out plays with the quarterback deciding to run or throw based on the defense's positioning. This is only one type of RPO. Ian Boyd of SBNation wrote a fantastic piece last year detailing the evolution of these spread concepts. The GIF below is borrowed from his article. Watch as the offensive line fires out on the snap causing the middle linebacker to react to a run read, only to have a pass thrown behind him.
To be frank, that play is impossible to defend as linebackers are charged with both defending the run and the pass. Had he instead chosen to drop into coverage, the quarterback would have simply handed the ball off. In the NFL, those linemen would have been flagged.
Personally, I think this rule change should be revisited. College offenses already have more latitude than their NFL counterparts on passes thrown behind the line of scrimmage - in college, linemen may drift as far as they like on the snap in these situations, while in the NFL they must stay within their one-yard window until the pass is released - so the only real effect of the rule change would be to require the pass to be delivered in the backfield. This makes sense, as the linebackers are given a fighting chance to rally to the football after it is caught and prevent a big gain. Assuming that such a rule change is a non-starter, and that better enforcement is the goal, the best solution would be to somehow incorporate instant replay.
Incorporating more penalties into the replay system is tricky business. The way the current system is designed, play could be stopped on every other play to review whether or not a penalty occurred. Considering the scoring that happens in college football these days, games are already long enough. I don't personally want an official in the booth looking at every single pass and stopping play any time he thinks a lineman drifted too far. There are, however, a couple of plausible replay solutions. In both cases, replay rules would be expanded so that all penalties dealing with time and space are reviewable. This could include offsides and offensive formation if a camera angle exists that clearly shows the line of scrimmage as well as the three-yard window. Offensive and defensive pass interference, holding, hands to the face, illegal blocks, etc. are judgment calls and should remain non-reviewable. The replay can then be incorporated in two ways:
1) Adopt the NFL rule that all scoring plays are reviewed. This is simple enough, and would allow the crazy plays like the one that happened Saturday night to be reviewed (Coincidentally, it was reviewed in order to overturn a flag for an illegal forward pass. The fact that the pass was reviewable and not the lineman downfield highlights the absurdity of the current rules). Plenty of game-altering plays happen that don't result in a score, however, which brings us to:
2) The coach's challenge. The way the current rules are set up, coach's challenges are rarely used or needed. Allow coaches to challenge that offensive linemen were downfield, and make challenges unlimited as long as they keep winning them. This obviously puts the onus on the coaches in the booth to pay attention, but at the very least some recourse would be available.
No system will ever be perfect, and as shown in the aforementioned GIF, even the three-yard window creates a virtually impossible situation for defenders. Taking that into account, better enforcement of current rules is an absolute must. Making it a key focus of the field officials should be the starting point, but a little help from instant replay can't hurt.