back row player NFHS rules
 

Can a back row player who's hands are completely about the height of the net in front of the attack line, set the ball for a front row team mate to kill it.

Yes, assuming the back row player is NOT the libero.

Yes, also assuming that 1) the set does not cross the net untouched, or 2) the set is not legally blocked in the plane of the net.

(You specified that the ball was going to a teammate, but sometimes those sets go slightly astray :) )

I should add, that if the player *IS* the libero, it doesn't matter when the ball is when it's set. If the ball is above the height of the net when it's attacked, it's an illegal attack.

Neither the setter's hand height, the ball position when the ball is set, nor the attacker's floor position matter one iota in this scenario. The only things that matter are:

• For regular back row setter, was the ball contacted entirely above the net AND does the set itself (NOT the subsequent attack) result in a completed attack? If either of these conditions are not met, then there is no fault.
• For a libero setting, are they located in the attack zone, was it using overhand finger action, was the subsequent attack contacted *entirely* above the net, AND was the attack completed? If ANY of these conditions are NOT met, the attack is legal.

Of course, the rules regarding a back row player completing an attack contacted entirely above net height while last located in the attack zone would supersede the above bullet points.

Hope this helps.