It snuck up on us, didn't it? None of us anticipated the NFL's confusing and at times absurd emphasis on roughing the passer penalties in 2018, one that has produced 30 flags through the first 47 games of the season.

So can we all agree not to allow a parallel trend to arrive unannounced as well?

Hiding in plain sight is the sudden realization of a strategy the NFL has been attempting to implement for years. For the first time in memory, the league is using ejections as a regular penalty for and deterrence against on-field behavior -- a potentially season-changing tool given the relative scarcity of NFL games.

We have seen fits and starts of this approach in the past, but nothing that approached the longevity of this effort. In the past 12 weeks of regular-season play, dating back to Week 9 of last year, 20 players have been ejected. That total includes five in 2018 and represents a pace that would double any 17-week total on record prior to the start of the 2017 season.

The origins include a confluence of commissioner Roger Goodell's priorities in recent years, sportsmanship and safety, and can be traced to efforts that began late in the 2015 season. It is a welcome development for many, and a consequence I've advocated for as well, but it is without question having an impact on games.

Sunday, for example, the Denver Broncos could not score after losing leading rushing Phillip Lindsay late in the second quarter of an eventual 27-14 loss to the Baltimore Ravens. Referee Ron Torbert said Lindsay dove into a pile and threw a punch, and it's reasonable to wonder if the Broncos would have fared better if their starting running back had remained in the lineup.

Lindsay said afterward that he was not punching an opponent but instead attempting to recover a loose ball. But Torbert's decision underscored the NFL's emphasis on using the ejection tool.

Ejections by season Year Ejections 2018 W1-3 5 2017 W9-17 15 2017 W1-8 3 2016 13 2015 4 2014 13 2013 6 2012 7 2011 8 2010 5 Source: ESPN Stats & Information

To be clear, referees have for decades resisted ejecting players for anything beyond outrageous behavior. Each game represents 6.25 percent of the season and carries an outsized impact on a team's fortunes, at least compared to the 162-game major league baseball season or the 82-game campaigns in pro basketball and hockey. As the table shows, referees issued an average of seven per season between 2010 and '15.

Neither the NFL nor the Elias Sports Bureau has tracked ejection totals over history, mostly because they have been irrelevant. ESPN Stats & Information records on ejections go back to 2001 and indicate there had never been an NFL season with more than 13 ejections before last season's run began. So as best as we can tell, the league has entered a record-setting era in this space.

Where did it all come from? You have to go back to December 2015, when the NFL office was livid that referee Terry McAulay failed to act more forcefully to a gamelong series of extracurricular pushing and punching between New York Giants receiver Odell Beckham Jr. and then-Carolina Panthers cornerback Josh Norman.

As the table shows, the NFL finished 2015 with only four ejections. Then, referee John Parry failed to eject anyone involved in a series of late-game incidents during a violent playoff game between the Pittsburgh Steelers and Cincinnati Bengals. The NFL spent that offseason encouraging referees to use ejections more frequently, and over the next two years added a series of rules that all but guaranteed it.

In 2016, owners approved a rule that required an automatic ejection if a player received two of a certain type of unsportsmanlike conduct penalties in the same game. This season, they mandated that referees eject flagrant violators of the new helmet rule. And, importantly, the league gave senior vice president of officiating Al Riveron the authority to add an ejection to any penalty a referee has called during a game.

When you add up those factors, you have the results we see today. The league has even ventured beyond ejections for sportsmanship and issued two this season for late hits on quarterbacks, the first such ejections since 2009, according to the website Football Zebras.

If the league continues the pace it started in Week 9 of 2017, it will have disqualified 28 players during a 17-week stretch. That's a 115 percent increase from what we can assume is the previous 17-game record, and more than the five seasons between 2010 and '14 combined.

I don't know of a way to measure whether the game is cleaner or safer with the legitimate threat of ejections hanging over players. I do know that I'd rather watch the Broncos with Phillip Lindsay on the field.

But I think we can all agree that there have been other games in recent history marred by behavior that could have been emboldened by a limited menu of consequences. The NFL has fully opened its toolbox for dealing with those situations, and the results are hiding in plain sight.