What are the stroke fortune-telling methods?

Why is the word "sword" calculated by fortune telling as 13 painting? What is the basis? How to calculate strokes? I looked up the Kangxi dictionary, and there were only nine paintings.

Many radicals have to be changed when measuring characters.

For example:

Grass prefix-calculated by "grass" stroke;

Next to the vertical heart-calculated according to the strokes of "heart";

Next to the hand-according to the "hand" stroke calculation;

The word "Wang" next to it-calculated according to the "jade" stroke;

Go- calculated according to "Go" travel;

Left ear knife-calculated according to the stroke of "Fu";

Right ear knife-calculated according to the stroke of "Yi";

…………