First-timer application rate refers to the number of first-timer applications divided by 95% of the total flat supply, while second-timer application rate refers to the number of second-timer applications divided by 5% of the total flat supply. (However, some flats are also set aside for quota-based priority schemes, where HDB does not differentiate between first-timers and second-timers. At least 95% of the remaining flats are then set aside for first-timers. Where the number of units is less than 20, all the flats will be set aside for allocation to first-timer families. Second-timer families may still apply for these flats. They will be shortlisted if the number of applications received from first-timer families is less than the flat supply) - taken from HDB site.
So if at least 95% is reserved for first timers, in this case it would be 469units x 0.95 ~ 445 and only about 24 (5%) for second timers...why are there potentially 100+ 2nd timers ahead of me, vying for mere 24 units available for them or is there a system once 24 2nd timer units are taken, the rest infront will be informed 2nd time quota filled? thanks!