imp thing local iri mem/admin who know about the route can easily analyse
it depends on each trains,
since rlgn , qouta systm varies also help's mem to predict if any end to end seats avl form source
and
end...
more... to end easy to predict since qouta is gnwl
and this site's history of particular train also helps mem/admin via pnr super search
etc many things are there
also mem /admin can add some ans if i left any or feed backs welcome