Federation - initial play, deflected off F1
 

Situation: Runners on 2nd and 3rd, a very sharply hit infield grounder goes up the middle, and hits the pitcher, deflecting it to the left. F6 changes direction to go after the deflected ball, and this puts the advancing R2 in her path to the ball.

Is there any exception recognized by Fed in this initial play situation for a ball hit & deflected so sharply that the runner had no chance to avoid being in the way?

Nope, no exception in NFHS which really does not make any sense. They do recognize a ball deflected by the pitcher hitting a runner the runner may not have a chance to avoid so there is an exception in that instance, but none for a fielder who is still in the act of an initial play per the rules.

soon to the point the runners cannot leave the base until the defense has fielded the ball :)

So when the deflection off F1 causes runner, fielder and ball to be on a 3-way collision course:

If ball hits runner, and a split-second later the runner and fielder meet, we play on.

If it happens in the opposite order, dead ball, INT.

I'm not sure. Why is it not interference? The ball was within a step and a reach of the fielder at the time of the interference. I'm not sure how hitting the player makes any difference to that.

Step & reach applies after a muff, not starting position.

Yes that's true. But I'm not sure it's relevant to my point. The fielder is protected from interference while making the initial play on the ball. I don't think the fact that it the ball hit a runner changes that. If she has a play on the ball the runner must give way.

On further consideration of my own comment, I feel that, though the ball hitting runner doesn't in itself kill the play, the contact of runner and fielder could, especially if it is a split-second later.

The rationale is the runner is expected to evade a fielder changing direction at all costs (not so much a ball changing direction).

So if all three elements are on a collision course, runner (though she can't avoid contacting the ball) should still be concerned with avoiding the fielder.

IF the ball is still close by.

If it ricochets off the runner, well away from fielder, we can play on...