There is an interesting assumption embedded in the HSC, that if a student is capable of doing more, why not? Ten units is all that is required for an ATAR, yet many students carry 12 or even 14, justified as a "safety net". It sounds sensible, but perhaps we should question why the "safety net" has become expected.
The obvious argument is that extra units provide protection. The HSC is unpredictable; a student who expects to excel in maths may suddenly perform better in business, while a supposedly "easy" subject can become one that disappoints. More units do create options while also broadening a student's intellectual experience.
Interestingly, the UAC reports that students who study more units tend to achieve higher ATARs, but that does not mean that there is a direct correlation between more units and higher ATARs. Instead, it points to factors such as motivation, effort, interest and time management. Most likely, the students doing more are already students who are highly driven. If so, "more units" may be less of a strategy and more of a characteristic.
Additionally, there is the scaling, which makes the idea of a "safety net" even more complicated. Scaling is a legitimate part of how the ATAR compares students across different courses. This makes subject selection even more of a strategic decision: is it better to choose a subject in which you are likely to achieve an excellent raw mark, or one in which your performance may translate more favourably after scaling? The problem is that there is no universally "safe" answer. Even scaling itself is not fixed and is recalculated each year. Therefore, the supposed "safety net" begins to look less like certainty and more like a calculated risk.
The safest subject may simply be the one in which a particular student is more capable of performing well. If an additional subject genuinely expands a student's options, interest or resilience, it may be worth carrying. However, if it exists solely because students are afraid, perhaps the bigger risk is spending two years preparing for a possibility that may never matter.
