[Coach_Owens87]

You know they should outlaw tackling altogether. I found this interesting fact about head injuries:

Minor head injuries, like concussions, are cumulative.
Although a third of head injuries are due to football, boxing is another sporting activity with a high number of deaths reported.
Athletes who sustained repeated concussions were often using their heads unwisely, illegally, or both.
Transient confusion with no loss of consciousness account for more than 75% of all sports-related brain injuries.
In football, injuries to the head result from making a tackle (43%), being tackled (23%), blocking (20%), or being blocked (10%).
Football head injuries are twice as frequent as neck injuries.
One of every 5 high school American football players, suffer a concussion annually.
The risk of sustaining a concussion in football is 4 - 6 times greater for a player who has sustained a previous concussion.
Football has the highest rate of concussion with an estimated 100,000 injuries annually .
Resources::

Cantu, R. C. (1998). Return to play guidelines after a head injury. Clinics in Sports Medicine, 17, 45-61.
Cantu, R. C. (1996). Head injuries in sport. British Journal of Sports Medicine, 30, 289-296.
Thurman, D. J., Branche, C. M., & Sniezek, J. E. (1998). The epidemiology of sports-related traumatic brain injuries in the United States: Recent developments. Journal of Head Trauma Rehabilitation, 13, 1-8.

Football is a full contact sport. If you don't want to risk an injury, don't play. Seriously, I don't want to see any player get hurt at level of football, let alone any sport. But the risk still exists in football no matter how you tackle your opponent. Now, the face mask is different. Spearing too. Chop blocks are allowed only in a specific area. Knee injuries are the # 1 injury in football, no doubt. But its still leagal to block below the knees in a certian radius of the line of scrimmage. It's still going to happen (horse collar tackles) to save a TD, and take the penalty, but you still save the score. IMO, when they are tackled by the collar it is a last resort to save a touchdown. [B]If you tackle by the jersey is it the same as a "horse collar"? Same kind of tackle isn't it?

[/B]

Not really, the force you generate from grabbing a solid collar, compared to a jersey isn't close.