How much aggressiveness is required to successfully obtain a seat on the subway or bus during rush hour? (Assuming the competition is not elderly riders.)
Not sure I understand your question. I prefer to stand if there is only a single seat, but I have not witnessed any fighting behavior over a seat. Whoever gets there first, will take it. No questions asked.
The strategy I use is to stand between the two of the long rows, and at each stop when it looks like someone is about to get off, I move towards the seat so that everyone knows it’s mine. It works pretty well.