Join Date: Jan 2015
Location: West Palm Beach, FL
Trace each skirt on the wall extending beyond where they go. Where they intersect is where your joint should be. For laying that out, make sure you're the same distance to the nose/riser on each tread to the top of the skirt board. As it stands, it looks like the top of the upper skirt is taller (further away from the nose/tread) than the bottom of the same piece.
The pitch/angle down IS going to change because of the change in the steps. If the steps were radiused the same and had equal tread widths to the section above it at the skirt, the pitch would remain the same. However, because of the radius, the treads are much wider at the skirt board on the curved portion than the straight area above. That translates to less pitch per rise which means a shallower angle.
Since the pitch changes, the best you can do is make it look normal (which it is normal) and keep the skirt boards parallel to the nose/tread all the way up the stairs.