Have you consider about the lie angle when you choose iron clubs.? Do you understand how much influenced to the result if the lie angle is not suitable for you?
The angle deviation of the direction can be calculated by mathematics though it is a bit troublesome at times .
First,you express the face of the iron by the equation.
Then you calculate the angle of the face normal and the direction of the target for different loft and lie.
As you know, when you hit the ball with upright lie then ball goes left, and when you hit ball with flat lie then ball goes right.
Is this influence the same when it has more loft and less loft?
Try to image 3D view in your mind.
If the loft angle is 0 degrees, it doesn't influence to direction with any lie angle.
The influence of the lie angle increases by having more loft.
Let's calculate it by our YUJI GOLF " TECH BASE ".
An example) deviation of the lie angle is 5 degrees
Loft 15 deg ----> 1.34deg
Loft 25 deg ----> 2.33deg
Loft 35 deg ----> 3.49deg
Loft 45 deg ----> 4.98deg
Loft 55 deg ----> 7.10deg
"Loft 45 deg ----> 4.98deg" means
100m ahead 100*tan(4.98) = 8.72m out from the target.
The face turns to the left of 8.7m(right) 100m ahead even though you swing straight because the lie angle deviated by five degrees.
Ball trajectories in curve directions eventually increases more, because it also influenced by the side spin . In this issue I never mentioned about side spin.
Do you get the idea of this effect?
Ever a customer did requested me for lie angle adjustment:
"All of my irons goes to the left. ,please bend all the iron's lie angle flat a by one degree."
As you know one degree effect for #3iron and short iron is totally different ?