Mallard photostack D850 focus shift play

Well I got my new lens which made me happy so I had to try it out. Very confused by what happened I first tied a stack of 100 photos stacked with a movement of 4 out of 10 and got about an inch in focus. This photo was a stack of seventy with a movement of 10. I can see I need to play a lot to get to understand this but I have seen people doing small macros with a movement of 1 and waterfalls with a focus movement of 5 so I really need to get my head around it. The good thing is that it does work and after a bit of playing I should get to understand this and get it doing what I want each and every time