The method of how i play is dividing 1 screen distance into 8 equal parts.

There are 4 steps to follow in order to get 3in1:
1) Determine the windless power to be used.
2) Power Adjustment.
3) Checking distance.
4) Angle Adjustment.

Step 1) Determine the windless power to be used.

Windless 3in1 power and angle chart:

4 Spin (need tail wind or up wind):
Attacking right -> 4.5-4.7
Attacking left <- 4.1-4.3

Step 2) Power Adjustment.

Calculating the correct power to use.

Height difference:
Low power: +0.05 for higher height of 1 bots height, -0.05 for lower height of 1 bots height.
High power: +0.05 for higher height of 2 bots height, -0.05 for lower height of 2 bots height.

Calculation: Orginal Power +/- wind x Factor

Why is there 2 Diagrams?
Because the longer the bullet stays on air, the affection of wind will be larger. So, needed more adjustment to overcome the force.

Step 3) Checking distance (checking what is the basic angle to use with the calculated power).

Power Chart:

for high tail wind, use the larger angle.
Noticing there are 2 angles in some boxes?
For against wind, use the smaller angle. For tail wind, use the larger angle

Step 4) Angle Adjustment (to overcome the wind force).

This angle adjustment chart is by - k n a t - ShenPu.

Calculation: Original +/- Wind x Factor