As I didn't know you receive one for reaching 1st every week and remember someone saying (I think it was bitcoingirl) who mentioned we needed 18 games correctly predicted to have a hat donned on you.
But this is great to know so to make a better effort in the predictions for next week's round.
I can not remember if I have such talk but to be a round winner there are no certain games. It depends on number of points you earn from the specified number of matches. Normally a round has 10 matches but we see sometimes round with 12 matches or 8 matches in case teams reschedule their kick offs. Whatever the match number, if you achieve highest point then you are yellow cap winner.
Congratulations winning the first round.