Update: The NFL wisely decided (at least for 2019) that a Hail Mary won’t be treated any differently than other pass plays.

The NFL’s plan to make pass interference penalties (and non-penalties) reviewable by instant replay was voted into existence at a league meeting in March. It lasted less than two months before getting its first adjustment.

NFL owners gathered at their annual May to discuss rule changes and other proposals, with the complicated PI rule at the top of their to-do list. And while Robert Kraft, Jerry Jones, et al. didn’t change the policy themselves, they effectively kicked it back to the rules committee for tweaking — likely giving coaches the unprecedented power to challenge interference calls and no-calls in the final two minutes of either half.

It’s a small change that shouldn’t have much of an impact on the field. Any replay flag in the final two minutes would already be filtered by one set of officials or possibly two — the ones on the field and the ones in the replay booth if the committee keeps the booth review intact on top of the coaches’ challenge. Coaches will be reticent to risk a valuable timeout in a close contest without the obvious video evidence to make a game-altering change.

But it only takes one instance of a bent or broken rule to make the NFL look stupid. And because this is a league with a single-spaced, size 10 font, 89-page rule book, this will not be simple.

The most obvious way to overthink this new reform is to point out how the jostling and jockeying for low-percentage, last-ditch Hail Mary passes could easily be flagged for pass interference upon replay. The league’s answer to this, presumptively, will be to exempt these plays from review.

And if NFL changes PI challenge rule, one issue is how they exempt Hail Marys from challenge -- league does not want every Hail Mary challenged. Members of committee indicated they will likely have to define what a Hail Mary is and include that in the rule. — Judy Battista (@judybattista) May 22, 2019

That’s great! But, uh ...

What exactly constitutes a Hail Mary?

Exempting Hail Marys from pass interference reviews makes sense whether these are initiated from the booth or by a coach. Teams shouldn’t be bailed out on desperation plays with little chance of succeeding unless the interference is blatant enough for officials on the field to see — and as retired offensive lineman and SB Nation writer Geoff Schwartz says, it’s one of the few areas where defenses retain a bit of an advantage in a league that’s made passing easier and easier in recent years.

But how do you define that high-risk, high-reward play that can shift the fortunes of a game’s final seconds? These last gasps at the end zone are mostly the high-arcing passes Aaron Rodgers has turned into an art form, but there’s no set mold for the Hail Mary. If you apply a catch-all net of “any play in the last seven seconds of a one-possession game,” you’d also exclude higher percentage plays that begin closer to the line of scrimmage in the process.

Would the Miracle in Miami and its litany of laterals have met the criteria for a Hail Mary?

Let’s say you extend the Hail Mary definition to passes that travel at least 25 yards in the air. Where would that leave the Minneapolis Miracle, which came with 10 seconds left in the game from a range where a big-armed quarterback could theoretically have found the end zone, but decided to hit Stefon Diggs at the Saints’ 35-yard line instead?

Does a pass have to make it to the end zone to make the argument it is worthy of review? Is there a minimum spot the ball has to reach in order to be considered reviewable and not just a last-chance effort for coaches to extend a game they would have otherwise lost? Do you institute a sliding scale of how far a pass has to travel in the air to define a Hail Mary based on a quarterback’s arm strength or the height and reach of his receivers?

The league needs to figure out all these scenarios to avoid a nightmare like last year’s Tommylee Lewis no-call derailing a meaningful game, which eventually led the owners to allowing pass interference to be reviewable in the first place.

Unfortunately for the NFL, the essence of a Hail Mary may be closer to Potter Stewart’s threshold for obscenity — words struggle to articulate it, but you know it when you see it.

There are a lot of moving parts to consider in order to keep this rule from becoming an albatross strung around the neck of the final seconds of seemingly decided games. Moving parts aren’t exactly the NFL’s strong suit when it comes to on-field rule changes, either — as evidenced by the last decade of debating what is and is not a catch.

Figuring out a Hail Mary should be slightly simpler, but it will still be a sticky wicket for the competition committee. So how does the NFL fix this?

My flawed, first pass at defining the Hail Marys that should be exempt from coaches’ challenges

Let’s start here. For challenge purposes, a Hail Mary is any pass that travels at least 40 yards in the air from the line of scrimmage in the final six seconds of the first half of any game or the final 10 seconds of the second half of a one-possession game (i.e. an eight-point lead or less).

That keeps shorter, potentially game-changing passes with a higher success rate under the protection of a coaches’ review. It also keeps the contact that comes as a deep pass hangs in the air from additional scrutiny and overwrought decisions.

But this isn’t perfect. It would also prevent teams that may need a big play just to set up a field goal or second Hail Mary from using a challenge to ensure a fair deal on the long shot that sets up their long shot. Adding language that clarifies the pass has to land inside an opponent’s 20-yard line would help, but it still wouldn’t fix everything.

That’s the problem. Football has so many loopholes, and the committed analysts who examine every inch of them, for any simple rule to last too long without being exploited. That’s why other recent reforms — quarterback protections, for example — have erred on the side of being overly strict, occasionally to the point of confusion.

If the league does allow coaches to throw their challenge flags on pass interference calls and no-calls in the final two minutes of either half, expect approximately 500 words of rule book legalese to define just what does and does not constitute the broad term we once used to mean “a long bomb at the end of the game with almost no chance of succeeding.”

It’s not a done deal yet — the competition committee and senior vice president of officiating Al Riveron still have to chat with the coaches this June before rewriting its proposals. But if NFL does decide to explicitly categorize certain passes as “Hail Marys,” get used to Dean Blandino explaining it to you every Sunday, starting in September.