Research studies on health and safety have offered differing opinions on practice regimens. Now even NFL teams are taking different points of view when it comes to practice contact.
On one hand, the Chiefs are doing most of their heavy contact drills early in training camp.
Two years ago, Todd Haley had the Chiefs playing the equivalent of two-hand touch throughout camp, and the result was a team woefully unprepared for the start of the season.
Hugging was preferred over tackling under Romeo Crennel last season.
Well, all of that is out the window with Reid, who promised during the hands-off offseason program that, well, the gloves would come off when training camp rolled around.
During his time with the Eagles, Reid preferred to hit hard early in training camp and then taper off as the regular season approached. The idea was to toughen up the team early on, and then give them time to heal before the start of a 16-game grind.
The change has left all Chiefs players with a different mindset.
"Do you hit Jamaal Charles full speed?" cornerback Sean Smith said, repeating a question from a reporter with a smile. "If the drill is live, yeah, you have to.
"You definitely have to take care of your teammates. You don't want to take any cheap shots or anything like that," he said. "But this is football. If we don't hit them, somebody else will."
On the other hand, the Carolina Panthers are de-emphasizing hitting and want more form tackling. Coach Ron Rivera wants players wrapped up, not tackled, during training camp.
Rivera said how teams have approached teaching tackling "has changed a lot" in recent years out of necessity.
Rivera now oversees practices where players get yelled at by coaches if they take an offensive player to the ground except during "live drills," which are few and far between at training camp.
Defensive tackle Frank Kearse, linebacker Ryan Rau and cornerback Josh Thomas were among the players at Monday's practice at Wofford College who heard it from coaches when their wrap ups turned too aggressive and the offensive player finished the play on the ground.
"Stay up," Rivera screamed at one point during practice.
"No tackling," screamed another assistant coach.
Some players said that's easier said than done and it's a skill that takes time to learn. There's that natural tendency to want to run a ball carrier into the ground and finish the play with a sense of authority.
But Panthers veteran linebacker Chase Blackburn, who won two Super Bowls with the New York Giants, said that's the reason the league has four preseason games.
"You tackle in those games and you get enough reps to where you get it going," Blackburn said.
-- Bill Bradley, contributing editor