RB with the ball hits the pile, is stopped, but still churning his legs. After a second or so with no movement, you take your breath in to blow it dead, and just before you blow the whistle:

A) the ball flies out
B) the pile begins moving forward
C) the pile begins moving backward
D) RB intentionally tosses the ball backward to a teammate.

In which cases to you go ahead an blow it dead as you were just about to?

It is difficult to give a definite answer as your question is posed. In all cases, if in your judgement, the ball became dead by rule, then blow it dead. If you judge that the ball is not dead by rule, let the play continue. We have all been there. Just as you blow the whistle, the runner breaks loose for a gain of additional yardage or fumbles with the defense recovering. One team is going to be unhappy. Most still do not understand that, with this type of action, the ball is dead when an official judges it to be dead, not when the whistle sounds.

I guess this was more of a general practice question than a rules question. I'm more wondering if once the thought appears in your head to stop the play - does a last minute change stop you from stopping the play - and if so, which kinds of last minute changes.

Changes locked out
 

Clearly, once you have a dead ball, you should kill it no matter what happens between your decision and the whistle. Whether or not I personally succeed in doing this is tough to say - I haven't been specifically watching for it.

Here's a dramatic example: One game I did at HL, the QB was wrapped up in the end zone, but still struggling. He got a forward pass off, and then about two seconds later I hear a whistle from the R. He ruled that progress was stopped in the end zone and awarded a safety.

I try (TRY!) to not alter my decision based on what happens afterward. Last night, RB was stopped for a second or a second and a half. Just as I'm about to blow it dead, he falls forward in a pile .... over the goal line. I blew it dead. I would have blown it dead if the ball flew loose. I would have blown it dead if the player tossed it to another player.

Explaining this one to my sideline was not fun, as they did not score afterward. But I stick by it. My logic - it was dead when I decided it was dead - subsequent actions (no matter who they favored) be damned.

But I did want to solicit the opinions of this esteemed (usually) board.

This is the most important concept in football...
 

Forward progress is perhaps the most important concept in football and also where our consistency has to shine forth on every down.

The California Official's Association (of which our local association here in Hawaii is an affiliate member) has some excellent training materials, one of which is an article authored by one of their members on the subject of forward progress. Perhaps the gentlemen from California will know which one I'm talking about.

In most running plays forward progress is the most forward spot of the ball in a runner's possession when the runner is held, grasped, etc. and otherwise controlled by defenders.

This is a good one to work on this week because we can think about it every down instead of just going through the motions. If we do this then the proper consistency will naturally follow.

I agree with what most are saying. I am a wing offical, once I decide that forward is stopped and I start to blow my whistle, the play is over. The action stops the play not my whistle.

Once you decide to stop the play anything happening after that doesn't matter. You see mentally, you have already blown the whistle (play over). Now you just have to let everybody else know the play is over by blowing the whistle that they can hear. Promptly killing the play with the whistle is critical because if the ball does come out and the whistle hasn't been blown, the gaining team is not going to be too understanding about your "mental" whistle.