Ok so I note the replies and agree with them.
But, and maybe I'm being a bit pedantic here,
the statement 'bad in a horizontal configuration'
is a bit of a generalisation, there was no
reference to thickness, size & spacing of support etc,
I wouldn't use it as a baseboard for the reasons
which have been quoted, but the point I was trying
to make is, there are situations where chipboard
performs well 'in a horizontal configuration',