Goalie shot clips (a test of the tracker's puck on these clips; your clicks are the truth it is scored on). Click the middle of the puck if any part of it is visible. One click saves it and moves on. No puck in view: press N. Puck fully hidden, or you cannot tell: press C.
Click = puck centre (next frame). N = no puck visible. C = can't tell. Left arrow = back (then click again to redo).