it only works on the tenth throw.
if you zoom in, you can see a glowing red spot in the black.
you have to hit it, the only reason it can only work on the tenth throw is that the wall needs to spread out enough for you to hid the red spot.
and it's only wide enough on the last throw.
i can do it whenever i please.
if you (from the start) turn to face between the second and third pins back. and move all the way to the right (or left, just go the direction you turned) and throw the ball up in the air, it should go down the rail. it may take a little practice though.