We did a presentation in 2018 regarding many scenarios that could occur when a back row setter faces a front row blocker at the net, here’s a video that outlines all the decisions a referee has to consider during such plays.

This setter is back row.  It appears from the net cam that the ball barely broke the plane of the net.  If so, then the blocker can contact the ball legally.  Since the back row setter was involved in a joust, the call should be a back row block on the setter. (Rule 9-5-5a)

If you believe that the ball did not enter into the plane of the net, then the call would be over the net on the blocker.

Here’s another one like that:

Here’s another one where the ball goes over the back row setter into the opposing team’s front row attackers where the ball is attacked into the outstretched hand of the setter.  This is also a back row block.  Oftentimes, a coach will say “How can my setter be a blocker?  She was trying to save the ball!” or “She was trying to set…that’s not illegal!”  According to Rule 9-5-1c, a player is a blocker if there is a ball coming from the opponent and if she is reaching higher than the net at the moment of contact.  There’s even a note at the bottom of the rule that says, “If a player near the net is reaching above the height of the net and opponents legally cause the ball to contact him/her, the player is considered to be a blocker.”  The intent of what the player was trying to do is irrelevant.  Check this out:

In a meeting once, we talked about a situation where it is a back row block if a back row setter setter sticks a hand above the net while the attacker smashes it on top of the setter’s head below the top of the net.  We talked about the fact if that her hand was above the net, that meant that she was a blocker.

So, here’s video of that exact situation.  The setter is back row. This is a back row block violation.

Here’s one where the back row setter just jumps while facing away from the net and contacts the ball. To be defined as a blocker, the player does not have to be facing the net, so this would also be a back row block.