This is technically a cheat, since you are using range(1, 1000).
You technically have to use range(1, k) where k=log(n + 1, 5).
It would break for really large numbers.

Inheriting from tuple makes most sense, as a vector basically is a tuple.
All the inherited functions should make sense.

Wouldn't max([s2, s1], key=score) be cleaner for the last line?

More importantly, that is only sorting the list once, instead of twice,
so it's more efficient too. Secondly, sorting twice would fail if
the sorting algorithm used wasn't a stable one (but it is in Python).

Someone's a functional programmer.

itemgetter is always such a dilemma for it.
I like how clean and nice it is, but I almost never
use it because adding a whole import just for it feels silly,
especially since lambda x: x[n] is just as long anyway.