Is is possible for the puck to hit a side post and still completely cross the goal line?

Question

Let me preface this question by stating that I'm a youth hockey ref, and we don't have video goal review in our games.

I had a situation the other night where a shooter fired a shot from about midway up the inside of the circle nearest to me, it hit the post nearest to me, and bounced out at an angle of (about 60 degrees) to the other side.

For me, standing at the goal line (probably 2-3 ft from the post it struck) it looked like it had completely crossed the goal line before bouncing out. I signaled a goal, and of course the coach argued emphatically that it wasn't a goal. His argument was that it was "physically impossible for it to hit the side post and bounce out in the opposite direction" and still have completely crossed the goal line.

So, my question is whether or not this is physically possible. In this particular situation, the goal post is itself wider than the goal line by probably almost an inch, so my suspicion is that, if it hit the inside corner of the post, it could bounce out at the angle we saw and still have completely crossed the line.

Obviously, this seems like it would be extremely rare, so whether or not I made the correct call is totally different, but I'm wondering about the physical potential for this to have happened.

Answer 1

The goal line on a standard rink is 2" and the dimensions listed on NHL.com for the diameter of a goal post is 2 3/8". Given a flat shot with the puck diameter of 3" and assuming that the dimensions were the same on the rink you were on, I think it would be impossible for the puck to hit the post and come out while completely crossing the goal line.

The only part of the post which is completely in the net is the last 3/8ths and for the puck to hit that part while being completely over the line and ricochet out, it would have to be shot from inside the net.

Answer 2

It's physically impossible for the puck to hit the post, cross the goal line and then go back over the goal line the other way, without some other object being involved, e.g. a player's stick. According to John Cullen's answer, the goalpost is situated ON the goal line, is essentially the SAME width as the goal line (NOT wider "by probably almost an inch", as you speculate), and is shifted slightly off-center toward the back of the net, therefore the side of the post is basically in the center of the goal line. At the time the puck hits the side of the post, it is, at best, only part-way over the goal line. NHL rule 78.4 states that the puck must be "entirely across a red line" in order to be scored, i.e. from a vertical perspective, separation is visible between the back of the puck and the back of the goal line. For the puck in forward motion to hit the post, then completely cross the goal line, then somehow proceed backward out of the net, on its own, would require rewriting the laws of physics and motion. So, if the puck hits the post and bounces directly out, it CANNOT be a goal.

P.S. As the back 3/8" of the post is in the goal (see answer referred to above), technically it's possible for the puck to be in the net at the time it strikes that part of the post at just the right angle. This would only be visible via a perfectly-positioned high-speed camera. The puck could still not then proceed out of the goal on its own.