This is a question that gets asked a lot and it’s an important one. How you compose tells a lot about the story. Sometimes that means the subject is centered and sometimes it does not. While the rule is having the subject centered yields the strongest image, that only works if all the other elements support it. So what does that leave you with? When working with a moving subject you have to be reading the direction the subject is moving. You have to anticipate where it is going so that you end up with a shot where the subject isn’t centered nor cut off on the sides. This Bucker Jungmeister is a good example.
This shot was taken at EAA AirVenture Oshkosh last year with the D5 and 200-400 VR. I saw the plane coming from the right and knew it would pass in front of me from right to left. Going into the shot I knew how to pan with it. In order to show this movement and tell the story the plane had to be off centered and in this case to the far left of the frame. If this was centered it wouldn’t be as strong. So when it comes to composing with a moving subject you have to merge the storytelling with the technical in order to show the true nature of your subject.