Welcome to the other side of the NFL's offseason of rule changes. From a new standard for the catch to increased prohibitions on the use of helmets in contact, the league is awash in jargon and amendments that will in many ways define the 2018 season.
What follows is a one-stop source for all the changes you need to know about:
Helmet rule
In an expansion of the ineffective "crown of the helmet" rule, the NFL will now penalize players 15 yards if they lower their helmet and initiate contact with it against an opponent. Flagrant examples -- such as when the player has an unobstructed view of the opponent, or clearly could have avoided the contact -- could result in ejections. All ejections will be reviewed by senior vice president of officiating Al Riveron and/or his staff in the New York command center.
This rule was the story of the summer in the NFL, as players initially expressed confusion and flag totals piled up during the first two weeks of the preseason. But a narrow clarification issued Aug. 22 reminded officials to overlook incidental or inadvertent contact from a lowered helmet. That tweak effected a 60 percent reduction in flags, to about 0.63 flags per game. For 2018, at least, the NFL has focused this rule on obvious infractions.
Reimagined kickoff
The NFL adopted a proposal from special-teams coaches that rebuilt the chassis of the kickoff, even if the exterior won't look much different. To reduce the high-speed collisions that cause concussions, the new rule prohibits the coverage team from getting a running start before the ball is kicked. Wedge blocks are outlawed, and eight members of the return team must line up within 15 yards of the restraining line. Officials also are instructed to blow the whistle for a touchback the moment the ball lands in the end zone.
One consequence of the rule is that offensive and defensive linemen almost certainly will be eliminated from the play. If these changes don't bring down concussion numbers, the NFL will consider a more radical overhaul next spring or possibly the elimination of the kickoff altogether.
Revised standard for a catch
The requirement to "survive the ground" has been eliminated -- a change designed specifically to avoid future instances of counterintuitive rulings that spurred debate about plays involving Detroit Lions receiver Calvin Johnson (2010), Dallas Cowboys receiver Dez Bryant (2014) and Pittsburgh Steelers tight end Jesse James (2017). A receiver must now control the ball, establish himself in bounds and perform a football move -- such as a third step or a lunge -- to make a legal catch. This definition applies to players who are standing or going to the ground. It remains eligible for replay review.
By rule, receivers can make a legal catch and still be in a defenseless position afterward, meaning that approaching defenders must be extra careful in avoiding the head and neck area when they try to break up the pass. Some officiating observers, including former NFL officiating chief Dean Blandino, think this rule will swap one set of debates for another. Among them: Did the receiver, in fact, perform a football move? There is also some concern that passes once ruled incomplete will now be ruled a catch and fumble.
Slight movement of ball allowed in catch
As part of the catch rule change, the NFL added a subtle but important clarification to its case book that notes: "[I]f the ball moves within control of the receiver, he is deemed not to have lost control of the ball and it is a completed pass."
This tweak should prevent the kind of technical replay reversals we saw in 2017, most notably when Riveron overturned a touchdown catch by Buffalo Bills receiver Kelvin Benjamin in Week 16. Benjamin had secured control, but then the ball moved slightly as he stepped out of bounds. He was not in bounds when it stopped moving.
Stephen A. Smith breaks down how the increase in replays slows down the game and makes it less enjoyable to watch.
Body weight into the QB
For years, roughing the passer has included a prohibition of "unnecessarily or violently throwing down" the quarterback or landing "on top of him with all or most of the defender's weight." But after seeing injuries occur even when the contact falls short of a violent throwdown, most notably when Green Bay Packers quarterback Aaron Rodgers broke his collarbone, the league has asked officials to call it tighter in 2018.
Per the instructions: "The defender is responsible for avoiding landing on the quarterback when taking him to the ground."
Impact was obvious this summer. During the preseason, there were 51 flags for roughing the passer, according to ESPN Stats & Information research. That represented a 131.8 percent increase from the 2017 preseason.
Illegal contact emphasis
In part because scoring decreased 4.6 percent in 2017, the NFL will emphasize rules regarding pass defense in 2018. That includes defensive pass interference and holding, but the major foul to focus on is illegal contact. Officials will more strictly enforce the rule that limits contact by a defender against a receiver to within 5 yards of the line of scrimmage. It also prohibits defenders from using hands or arms to contact the receiver unless it is to defend or protect against impending contact.
Officials threw 38 flags for illegal contact in 2017, down from 64 in 2016 and 86 in 2015. That trend will reverse in 2018.
Ejections from New York
For the first time, Riveron will have the authority to demand the ejection of a player who has been penalized for a non-football act. That covers incidents such as fighting, punching and post-play hits. It does not include "football acts," such as roughing the passer or a hit against a defenseless receiver. Importantly, Riveron can't order the ejection if a flag hasn't already been thrown.
Referees also will retain the authority to eject, but the NFL instituted this option because it has failed in recent years to eject players when merited. Among the examples: fighting in 2015 between New York Giants receiver Odell Beckham Jr. and then-Carolina Panthers cornerback Josh Norman, and a 2017 late hit by New England Patriots tight end Rob Gronkowski against Buffalo Bills cornerback Tre'Davious White. Under the new rule, Riveron would have the authority to eject Beckham and Gronkowski.
Marking headfirst slides
This tweak hasn't received much notice, even though officials spoke openly this summer about its potential impact. Players who slide headfirst, usually quarterbacks, will be judged to be giving themselves up -- much as they are when they slide feetfirst. As a result, the ball will be marked at the point where the player's body first touches the ground, not where his forward progress ends.
The intent was to address concerns of defensive players who avoided contact with a player sliding headfirst -- allowing the player to gain extra yardage -- for fear of penalty. The practical consequence, though, is significant. A player who appears to have crossed the line to gain or goal line on a headfirst slide, via forward progress, could have the ball marked well behind it. Diving could result in lost first downs and touchdowns.
No PATs at end of regulation
Teams will no longer be required to kick a meaningless extra point, or kneel down, after a score on the final play of regulation. This situation arose in the divisional round of the 2017 playoffs, after the Minnesota Vikings' game-ending 61-yard touchdown play against the New Orleans Saints. The play put the Vikings ahead with no time remaining, but the teams were still required to reassemble for a PAT play. That will no longer be necessary.