How can political parties decide where to focus their efforts in a Singapore election? The answer lies in purchasing the Registers of Electors.

The Register of Electors contains the list of electors for a particular SMC or GRC, known as a electoral division.
Each electoral division is separated into a  number of electoral districts.

So, once a political party have purchased the Register of Electors, it needs to distribute it to its polling agents.
And when electors register their presence at the electoral district, a party's polling agent can mark the name of the elector.

Once voting is completed, during the counting of votes, the candidate can use the register of electors to figure out what percentage of support it got for a particular district within an electoral division. And then, it can look at areas where it is weak, and focus on a particular district to canvas support.

That way, it'll be able to drive up support for the next election.