
The idea is that graduating high school students who take the national exam (GaoKao) in June can take their score sheets and start to evaluate their scores. Then they compare their scores with the requirement of each institution in the past and choose which one they want to go. Basically, better institutions require higher scores.
This may not be the ideal system simply because the true scores are not given and each institution remains unclear till they know how many students are applying and what their scores are. However, it is the best available.
Source: Google Blogscoped