Chop Block vs Roll-Up Block From The Side - what's the difference?

[goheels22002]

I was reading about the rules changes for 2014 and have yet to see a decent explanation of the expansion of the "roll-up block" which was expanded from rolling up on a tackler's legs from behind to rolling up from the side.

I get that blocking from behind is the old clipping rule, and the rolling up on a guy's ankles and calves from behind can cause serious injuries. But blocking from the side seems fair unless you're deliberately going at his knees. Does this prevent a blocker who's on the ground from getting in the way of defenders in pursuit of a ball carrier or quarterback rolling out?

Is this outlawing the blocking scheme that Denver perfected when everybody diagonally went low to block defensive linemen but weren't exactly executing chop blocks?

Can anybody articulate what the new rule means and when it will be called?

 

[SB39]

As far as I understand it, cut blocking, which is blocking low at a guy from the front, is still legal. Many think it shouldn't be legal because it is targeting a guy's knees but for now it is allowed.

Chop blocking is illegal, which is blocking low at a guy from the front while he is already engaged with another blocker. What you can do to a defender who is loose is different from what you can do to a defender who is already being blocked by another player.

 

[PP2]

I get that blocking from behind is the old clipping rule, and the rolling up on a guy's ankles and calves from behind can cause serious injuries. But blocking from the side seems fair unless you're deliberately going at his knees. Does this prevent a blocker who's on the ground from getting in the way of defenders in pursuit of a ball carrier or quarterback rolling out?

Roll-up blocking is going at the knees from the side.

 

[goheels22002]

Roll-up blocking is going at the knees from the side.

I get that part, but this rule seems to apply whether the defender is engaged with another player or not. The refs can make a roll-up block call on virtually every play when offensive linemen go down. At the line of scrimmage, there will always be defenders around them.

 

[PP2]

I get that part, but this rule seems to apply whether the defender is engaged with another player or not. The refs can make a roll-up block call on virtually every play when offensive linemen go down. At the line of scrimmage, there will always be defenders around them.

If the defender is already engaged with another player, and gets a cut block, that's a chop block, no matter the angle of the cut block.

IMO, the roll up block infraction would be a matter of judgment on the part of the referee, if he thinks the act was deliberate or not.