In another thread, someone mentioned the one way service in the down direction that terminates at Eastleigh, AFAICT there is no pathing reason why the 0801 ex Winchester service couldn't start at Eastleigh and form the opposite working?
This popped up rather nicely for a question I had on the same subject... Where does the stock for 0600 LDS - PLY, 0615 LDS - SOU and 0632 YRK - PLY stable? Neville Hill?
Because starting a service at Winchester and terminating one at Eastleigh were decided on at different times :P
(The Eastleigh one used to go nonstop round the houses to Southampton via Andover for pathing/route knowledge reasons, plus so they could say it was six new Soton services rather than five; until they realized that they were carting fresh air south of Basingstoke as it got overtaken by three other trains.)