回複：12月畢業. Why better not 申請半年OPT?

if you use new I-20, the old OPT (based on old I-20) is canceled. It you get 6-m OPT, you can't apply for the remaining 6 months under the current new OPT rule (that you must file within 2-m of graduation) so the 6-m is wasted if you only apply for 6-m now. So, apply 1-y now, the 7-12 months may or may not be wasted depending on how you keep/change your status later.