How Liverpool FC 'reprogrammed' Jerome Sinclair ahead of first-team chance : Revealed: the intricacies of preparing a striker for a shot at the big time (James Pearce, 3/20/15, Liverpool Echo)
[F]or analysis purposes the penalty box is divided into five zones. The central area in front of goal is zone 1.
A line is then drawn from each post to the far corner of the box – creating 2R and 3R on the right as well as 2L and 3L on the left. Zone 2 is closer to the centre with zone 3 being where the angle for strikers is much more acute.
For a right-footer, the easier zone to score in should be 2R but prior to Christmas, Sinclair hadn’t scored once from that area. Reds staff were concerned that the kind of goals he had scored through the age groups simply aren’t netted at the highest level.