After you have evaluated all areas, train the area which has the highest number of shots.
What is your common mistake: Distance Control or Direction?
The distance to a certain length varies a lot
For a example a 130 target
And shots of 65, 105, 110, 130.
Every shot more or less the same distance but left and right
For example a 130 target
And shots of 127 (25 left), 128 (4 left), 132 (5 right) and 136 (18 right)