The beauty of being in charge of this blog is that I get to make all the decisions, in particular I have defined the geographic boundaries that I am working to. For example, I include the newish Royal Park Gate development in my definition of Ham even though it is (currently) in the borough of Kingston upon Thames.
The other contentious boundary is Petersham and here I show where I think the southern boundary of Petersham is. This is based on the evidence on the ground gathered from walking all of these streets regularly.
Note that my definition of Ham includes part of Petersham as I include everything either side of Petersham Road until the juction with Star and Garter Hill. This is because that is a natural boundary and before that there is a continuous built up area that includes all of Ham and this part of Petersham.