let's say A = 10 and B = 20

now we get

CA A C B CB

0 10 15 20 30

but if we take the combine between CA and C we get 7.5, not the 10 from A.

if you want the combine between CA and C to give A again it should be like this.

CA A C B CB

5 10 15 20 25

now CA = A - (B - A) / 2

which means, substract from A *half* the distance between A and B

subsequently add to B that same distance.

You can do lots of things.

The combin is the prinzip of the middle or midpoint and shows the common or shared experience (the relationship itself, if you want) of princibly independant humans or beings or entities or konstellations or whatever. F.e. you can do a combin between your radix and an ingress of the sun in Aries, and you get a chart for the year, the same with the moon and you get a horoscope for a month. And this charts are much clearer than the usual ways I know like solars etc etc.

Another example, lets say you have A and B with the combin in the middle.

A combin B

Now you can do a new combin between A and the first combin, placed on 25% of the distance between A and B, therefor I called them Quarter Combins.

The first combin shows the shared or common experience of A and B. The second shows the common experience of A and the relationship, means it shows f.e. the "role" inside the relationship etc. (Quarter Combins can be done with multible combins, take 3 times Person A and one time Person B).

Combins are somewhat like a commode with a mirror with movable wings (hard in english, hope its understandable). You can place the wings so, that you can see the back of your head, or you can see the other mirrors mirroring mirrors. (And of course thees viewpoints are overlapping, because the always shows the same thing, a head :-) or a relation.)

Infinite possibilities of viewpoints, but the more reflections are involved the less sharp/precise the results are. In the end you get "white noise".

My experience is, the more simply the proportion is, the more "substance" is contained: The basic combin has a relation of 1 to 2, and its more "substantiell" than Quarter Combins, which have a relation of 1 to 4. So I concentrate normally on simple relations.

So it is not a question of right or wrong. The option you describe gives results, but it is not the Supplement Combin. It is a different way.