Since all 6 man receivers are eligible, can there be intentional grounding if the quarterback takes a straight drop back, gets caught by a defensive player, then throws the ball to the ground at the back heels of the offensive player in front of him?
Based on your description there would not be a foul since there was a receiver in the vicinity. A couple of years ago the rule used to be that the receiver in the area had to have a reasonable opportunity to be able to catch the ball, but that rule has since changed. It no longer matters if you have a reasonable opportunity or not. The rule doesn't specify a distance for "being in the vicinity" so this becomes a judgement call.
The QB drops back and gets flushed to one side by two DEs. All offensive players including the recrivers have left the area and cleared the "tackle box" somewhere near the hashes. The QB throws the ball into no mans land. Is this imtentional grounding? There basically is no longer a tackle box. If so, how is the tackle box determined?
The tackle box disintegrates once the ball-carrier leaves it, so once you get outside that defined area, there is no longer a tackle box. Once the passer is outside the tackle box, he may "ground" the ball as long as the pass crosses or lands beyond the neutral zone or neutral zone extended.
In other words, there was only a center and wide guys. The center leaves the area and only the QB remains. At that point where does the QB need to go in order to have been considered to leave the tackle box?
the tackle box is defined as extending 5 yards from the snapper in each direction along the neutral zone and running parallel to the sidelines. that box extends from the neutral zone to the offenses end line (through the end zone) the tackle box goes away as soon as the ball leaves that boundry.
Fencewire is dead on with the definition of the "tackle box," which remains the same regardless of formation or whether you are playing six-man ball or eleven-man ball. In six-man, it can sometimes be a difficult judgment call for a referee on whether the passer gets outside of that zone (five yards away from the snapper's original position), but the box is "set" for that particular play as soon as the snapper is establishes and goes away as soon as the ball-carrier leaves the box.
The international grounding needs to be a discussion amongst the refs especially the white hats. Also they need to understand the penalty. I saw an intentional grounding called, which I disagreed with. They then walked 15 yards off from the spot of the foul. I think we now have 2nd and 45 because of walking off from where ball was thrown. These refs had not called many 6-man games and I would have been happier if they had taken rule book out of their pockets than having to get together and discuss the rules after nearly every flag. I have never seen so many holding calls made. It was stricter than when I played 11-man in early 60’s when you kept your hands at your chest. Penalties were not one sided. Everyone got called for anything that might have been a penalty.
Got video of it? IG is inherently a judgement call; to a smaller degree, holding is as well. I can't speak to if they really walked off 15, as it should be 5 from the spot of the foul and loss of down.
Where was the LOS?
and where (what yard line) was the QB when he threw the ball?
What position (1-5) was the ball at the snap? (1-5)? (helps determine tackle box on the field after the snap and kids start moving)
What yard line was the QB at when he threw the ball?
Where was the QB in relation to the tackle box when he threw the ball?
Did the ball reach the LOS?
Was there a receiver in the area?
All those questions are important and each brings a vital piece of information to the table to determine whether or not there was an IG foul, and if the referee thought there was, where it would be enforced from.