Roland Perry writes:
There are many ways that you can construct new rule sets. ...

True.

For people to be able to compare your "achievement" with that of others,

Y'know, that sounds kind of demeaning.

unless you are the first to do something [1], then you really need to
attempt a recognised task [2], and abide by a recognised rule set, which
the Guinness one is.

"Unless you are the first". *Is* anyone else known to have done that
before? Obviously Lynch wasn't aware of it.

"Peter" writes [rearranged for convenience in responding]:
Well I think this particular challenge was pretty pointless (but hey, it's
not like the standard Tube Challenge could be construed as anything but!),

Exactly! As pointless challenges go, I think it's as praiseworthy as any.

mainly because it didn't really set out all it set out to achieve.
... a lot of the lines have only been covered in one direction ...

That *was* what the person set out to achieve. All *routes*, not all
tracks.

Assuming there was a mistake in the write-up of the route and the
person did cover the District Line between Acton Town and Turnham Green,

No mistake; under the terms Lynch decided on, the District/Piccadilly
section from Ealing Common to Barons Court is one route and only had to
be done once. Lynch took the Piccadilly from Heathrow to Turnham Green.
--
Mark Brader, Toronto | "My ambition is to see a saying of mine attributed
| to Dorothy Parker or Mark Twain." -- Joe Fineman

My text in this article is in the public domain.