• 4D is one of the legalised betting activities in Singapore. The term “4D”refers to the 4-digit numbers ranging from 0000 to 9999 that can be bet on.
• Some punters may be inspired by “nice” numbers (such as 1888 and 8888) that they see on television shows, newspaper reports or car licence plates, and treat them as lucky numbers to bet on.
• In the 4D lottery system, there are limited times that each four-digit number can be sold. If a large number of people bet on certain numbers, those numbers become “红字”. Once the sales limit for a number is reached, punters will not be able to place any more bets on that number. Hence, the popular numbers are also known as “旺字” (meaning “prosperous numbers”) in Mandarin.

Some 4D punters were worried that this particular number would become a “popular number”, meaning they would not be able to bet on it in the two days before betting closes. As a result, they made their way to the Singapore Pools outlets as soon as they could to place their bets. (Shin Min Daily News, 16/9/2018)

• Examples of popular numbers in the past include 1157 and 0911, which represented the dates of the 2011 and 2015 Singapore General Elections (7 May 2011 and 11 September 2015), respectively. The numbers 8421, 1482 and 4281 also became popular numbers in 2018 as they were drawn multiple times.
• “红字” is different from “真字”, which refers to “lucky numbers”, or the winning combinations of numbers.