Studio Long Question

I am confused about the ridge count. When you divide the work for the neck, you have done 72, 78, 81 or 87 ridges. In all cases they are a multiple of 3 and so I understood that you ended with 2 A ridges and started the neck divide with a B ridge. Is that correct or should I have ended with 1 A ridge and started the neck divide with the second A ridge?

Then you do either 22 or 25 ridges from the split. The last ridge would then be a B ridge if you started with a B ridge, but the instructions indicate that you are ending with 2 A ridges. The only thing I can think of is that the cast on and first row (in A) count as the first ridge and so when you split for the neck you end with the first ridge in A and the first split row is the second A ridge? IS that right?

When you knit together the back piece and the front piece stitches are you knitting together a B ridge, a first A ridge, or a second A ridge? I guess that is the most important question I have.