A fumbles the ball near the sideline and the ball is loose on the ground recovered by B laying on the ground with his feet out of bounds. Who's ball is it? Which rule will codify this? Is the play dead if B just touches the Ball?
Not a NFHS guy, but I’ll bet the answer to this question is common to all rule sets for American football.
If a player has any part of his body touching the ground or something else (like a pylon) out of bounds when the ball touches him (or he touches the ball, however you want to look at it), then the ball is out of bounds, and dead the instant it touches the OB player. It makes no difference if the player has part of his body also touching the ground inbounds, and the ball itself is in the field of play or end zone when the touching occurs. The ball is out of bounds at that instant, and dead.
If the loose ball touched a pylon or the ground out of bounds, who’s ball would it be? Answer: The team last in possession. Same here.
So, dead and belongs to the fumbling team.
(And, officially, the ball was never “recovered,” since it was dead before it could be recovered.)