Dear Paperchicken,
Do you seriously think that other than Potong Pasir and Hougang,
anyone could ever win in any SMC? 
This has been actively debated among my comrades. I hole the view
that no one would be able to win any SMC other than those
previously won 10 or 20 years ago.
In strategic terms, these SMCs are considered as "killing field".
PAP is too eager to put up strangle hold on their monopoly power
and they are not here to make sure that there are enough SMCs for
opposition parties to contest, but rather, to divert opposition
parties' efforts into a battlefield that they could never win.

How do it? It is pretty simple. PAP made a mistake back in 1991 to
have SMCs up for snatch without much considerations. Later, they
are smarter, introducing elected Presidency. The elected Presidency
scheme was an effort for data collection, on the voting patterns of
Singaporeans based on "proxy opposition". That is why they set
"high" standards to deter any credible threat from any opposition
members in this contest. They fielded both trusted candidates of
their own, though one is viewed as "PAP man" as the other long
serving civil servant.
Why the need for such data collection? This is basically to make it
easier for boundaries to be redrawn, to exact precision, carving
out areas stipulated as "killing field"; ie. where support for the
PAP man is so great that it is not possible for any opposition
contestor to win. Of course, the common practice of dissolving
"danger zones" still exist; eg. like Cheng San, Eunos, Anson, Bukit
Gombak... etc etc.
Many opposition parties are too "practical" and think they could
possibly win a SMC. These are misguided views. These are the exact
places whereby PAP wants you to be there, so they could concentrate
their firepower with a proxy known advantage of support on the
ground!
On the contrary, I think it is much easier for opposition parties
to win GRC, provided they could come up with elements that could
sway the middle ground. This is especially so when the past
"stronghold" of PAP has been averaged out by various absorption of
"danger zones". To make it "safer them, they actually split
ChengSan into three pieces so to be absorbed by three different
GRCs, namely, Aljunied, Pungol Pasir Ris and Ang Mo Kio GRC. This
is to say that they are not confident about the ability of any of
these three GRCs to absord Chengsan as a whole. It reveals the
vulnerability of their GRC system.
Thus, I think for the next general election, if there isn't any big
changes, opposition could possibly win one GRC. As for SMC, I am
not that optimistic that any opposition party could break through
the two seats we have at present.
However, there is a catch here. PAP may choose to have a
Presidential election first, before holding the GE. The reason, as
given, is for sharpening up the precision of data collection. After
one decade, due to movements on the ground, the spread could be
very different right now. I think they will play safe and call a
Presidential election first.
Goh Meng Seng