Changing Your Target Line: Arrows or Feet?
What happens when you change your target line by moving your feet a board right or left? Is it the same as moving your arrow target? For simplicity, we'll use a straight ball, taking the lane oil and ball motion (hook) completely out of the picture, and look only at the geometry. We'll also assume you start on the approach about halfway back (7.5 ') from the foul line, you walk parallel to your target line, and we'll use some approximations about lane marking distances.
Now, let's look at those distances. From your stance position, it's 7.5' to the foul line; about another 15' to the arrows - a total of 22.5'. The pins are 60' from the foul line, or 45' from the arrows (twice the stance-to-arrow distance).
What happens when you move your feet (blue line)?
Using a line down the 20-board as base for the ball position, move your feet 2 boards left on the approach, and imagine a new line through the 20-board at the arrows, to the pin deck. That creates two similar triangles on opposite sides of the arrows. Geometry teaches us that similar triangles have all sides in proportion, so if the arrow-to-pin deck length is twice the stance-to-arrow distance, the ball will be twice the foot-move distance, or 4 boards right of the base line at the pin deck (opposite the direction you moved).
What happens when you move your target (green line)?
Keep the starting ball position on the 20 board and move your arrow target 2 boards to the left. The stance-to-arrow triangle is identical to the previous one, though pointing back at you (2 boards wide at the arrows). The stance-to-pin-deck triangle is similar to the smaller one, but now 3 times as large (22.5' + 45'), making the pin deck change also three times as large, or 6 boards, in the same direction as your target move.
In other words, for every 1 board you move your feet, your ball moves 2 boards in the opposite direction; for every 1 board you move your target, your ball moves 3 boards in the same direction.
What happens when you change your target line by moving your feet a board right or left? Is it the same as moving your arrow target? For simplicity, we'll use a straight ball, taking the lane oil and ball motion (hook) completely out of the picture, and look only at the geometry. We'll also assume you start on the approach about halfway back (7.5 ') from the foul line, you walk parallel to your target line, and we'll use some approximations about lane marking distances.Now, let's look at those distances. From your stance position, it's 7.5' to the foul line; about another 15' to the arrows - a total of 22.5'. The pins are 60' from the foul line, or 45' from the arrows (twice the stance-to-arrow distance).
What happens when you move your feet (blue line)?
Using a line down the 20-board as base for the ball position, move your feet 2 boards left on the approach, and imagine a new line through the 20-board at the arrows, to the pin deck. That creates two similar triangles on opposite sides of the arrows. Geometry teaches us that similar triangles have all sides in proportion, so if the arrow-to-pin deck length is twice the stance-to-arrow distance, the ball will be twice the foot-move distance, or 4 boards right of the base line at the pin deck (opposite the direction you moved).
What happens when you move your target (green line)?
Keep the starting ball position on the 20 board and move your arrow target 2 boards to the left. The stance-to-arrow triangle is identical to the previous one, though pointing back at you (2 boards wide at the arrows). The stance-to-pin-deck triangle is similar to the smaller one, but now 3 times as large (22.5' + 45'), making the pin deck change also three times as large, or 6 boards, in the same direction as your target move.
In other words, for every 1 board you move your feet, your ball moves 2 boards in the opposite direction; for every 1 board you move your target, your ball moves 3 boards in the same direction.
