In 2010, the NFL passed two significant rule changes to kickoffs.
Teams would now kick off from the 35-yard line, which was the case from 1974 until 1994 when the NFL moved kickoffs back to the 30-yard line. Also, players on the kickoff team were no longer allowed to get any more than a five-yard head start.
The year prior, in 2009, the "wedge block"—a strategy in which the front five blockers would come together and block similarly to an offensive line—was outlawed and replaced with the "two-man wedge," which is rather self-explanatory.
All these changes were in the interest of "player safety" and a response to the growing attention being paid to concussions and the NFL players who suffered them regularly.
So that begs the question, are these measures working?
While it's too early for any real qualitative data, I don't believe the rules are having their intended effect.
Moving the kickoff up to the 35-yard line was intended to create more touchbacks and in turn help drastically decrease the amount of kickoff returns.
While there are obviously more touchbacks, there are not as many as the NFL would have hoped. Special teams coordinators all around the league have obviously decided they're willing to risk getting trapped inside the 20 for the potential reward of a long return.
Unless the return man fields the ball nine yards deep in the end zone, most are coming out deep with a head full of steam.
So even though the kickoff team only gets five yards to accelerate, that is really offset by the fact that return men are now returning kicks from eight yards deep in their own end zone, something that would have cost them their job prior to the rule change.
Overall, there's just as much time for both sides to pick up speed and create those violent collisions the NFL wanted to all-but-eliminate.
The two-man wedge rule, while sounding good on the surface, only adds to the problem.
Before, when five guys were allowed to create a wall, they could substantially slow down the kickoff team by forcing them to run into that wall. Yes, those collisions were violent, but they were occurring, at most, within 35 yards of each other (assuming the kickoff team started 10 yards back and the wedge was set up 15 yards from their original starting point of 10 yards away from the kickoff).
The two-man wedge is obviously unable to slow down as many guys as the five-man wedge.
The NFL passed these rules with the hopes of ending the return for the most part, and figuring that even if a return occurs, the kickoff unit won't have as much time to get up to full speed and that will result in less-violent collisions.
Instead, the kickoff team is able to sprint down the field largely unopposed into a return man who has a deeper starting point than ever before, which is obviously allowing him to hit his full speed in the field of play much sooner.
The NFL should keep the kickoff where it is, continue allowing only a five-yard head start for the kicking team, but reinstate the five-man wedge in order to slow down the kicking team and prevent them from flying into the returner at full speed.
This combination would also mean fewer injuries at the wedge, since the kicking team is not going as fast as it could pre-2010.
As I said, any qualitative data presented as of now is not credible due to the small sample size. However, with the naked eye it certainly appears as though the NFL's attempt to legislate the return out of the game—but without the nerve to actually legislate the return into extinction—is coming up short of its intended goals.