I have moved a fireplace insert that had hardwood flooring right up to it. Now I have a straight line to work off of. How can I stagger that edge to add more flooring to cover the subfloor where the fire place was? I'm not close to a wall I'm more or less in the middle of the field. Do I cut the face off the boards? Do I remove a board from every other course? I don't know how to remove boards that are in the middle of a field.
Why don't you try a more novel approach, I do this often in such situation. I cut off all the ends of the boards that were formerly abutting the hearth. Cut them off square with the run of the floor, by nailing a straight strip on the floor, that is lined up so that a circular saw will lop off the ends with this guide. Next lay a mitered frame of the same floor boards around the edge of the space. This will make it look neat and tidy. Then you can fill in the space with floor boards that go in the same direction as the rest of the floor, or in the opposite direction.
Or, read my floor repair article in the Hardwood Authority section, it should explain how it's done to make a invisible repair. But in your case it may be simpler to remove the whole middle section of the floor and re-lay it, adding a few strips to make up the waste and missing pieces.
As always your Most humble servant, Joseph, the Wood Floor Doctor.