If you are doing sports work or other non-rectangular shaped structures, then you may have noticed a problem with Revit's Grid tool. It does not allow you to make a single Grid line that consists of multiple line and arc segments. We have come up with a few creative ideas that allow us to use multiple grid lines to make a single grid line.
For example, if need to create Grid line "A" that consists of four grid line segments, we call the first segment "A", and the following segments ".A", then "..A" and hide those bubbles. Not elegant, and it does cause some problems. I have been fighting this problem since 2004, so I would be interested in hearing how others are addressing this problem.