I've tried multiple times to understand field mappings and continue to be rather baffled. I assume it can be used to perform a geoprocess (in my case it will be a spatial join) and limit the fields in the output feature class. I'd like have the output only contain the fields generated by the spatial join (`Join_Count`, etc). I've tried creating blank field mappings objects and using it, but that's no good. I'd rather not take the extra step to delete all fields, as in large data set it will take some time. 

Can anyone provide help?