I find myself in the position of needing to travel between Kensington
Olympia and Wimbledon (usually in that direction) on a regular basis. I
am rather confused about the fares.

There are two routes - NR (change at Clapham Junction) and LUL (change
at Earls Court). As there's not much difference in journey time I
usually take whichever train is likely to depart first.

The NR ticket machine at Olympia helpfully has a Wimbledon button on it.
It doesn't say 'via' on it so I naively assumed that this is valid
via either route. However this ticket is issued as a single to U23
which seems to me to mean only valid via LUL. Further, the price of
this ticket (peak or offpeak) always seems to be £3, which looks
suspiciously like the LUL non-Oyster fare between zones 2 (Olympia) and
3 (Wimbledon).

On checking nationalrail.co.uk I find standard day singles at £3.40,
£4.30 and £5.60 (no indication of why the difference) and cheap day
singles at £4.20 and £4.80. (Why are the 'cheap' day singles dearer
than the cheapest standard day single?!)

So, I would appreciate answers to the following questions:

1. Is the £3.00 single (to U23) as issued at Olympia when pressing the
'Wimbledon' button on the machine actually valid on NR via Clapham
Junction? And, if not, why does the button not say 'via Earls Court'?
What would the penalty be if ticket checked on-train?

2. If the £3.00 single is valid via Clapham Junction then is Oyster
pre-pay (£1.00 from zones 2 to 3 at any time of day) valid via that
route also (which would be a real bargain compared to the cheapest
standard day single of £3.40)?

3. If answer to both of the above is no then why do the powers that be
not recognise that NR via Clapham Junction is nowadays quite a viable
route from Olympia to Wimbledon (and I guess to other NR/LUL joint
stations like Richmond also) and at least give a ticket machine option
for that?

Peter Kelly